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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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 */

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    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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 */

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    37

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#include "../../util/strdup.hh"

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    41

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

    42

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

    43

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

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

    45

    46

    47

class generate_c_st_c: public generate_c_typedecl_c {

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  public:

    50

    typedef enum {

    51

      expression_vg,

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      assignment_vg,

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      complextype_base_vg,

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      complextype_suffix_vg,

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      fparam_output_vg

    56

    } variablegeneration_t;

    57

    58

    typedef enum {

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      single_cg,

    60

      subrange_cg,

    61

      none_cg

    62

    } casegeneration_t;

    63

    64

  private:

    65

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

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     * by searching through the declarations of the variables currently

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     * in scope.

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     * 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.

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     */

    78

    search_fb_instance_decl_c *search_fb_instance_decl;

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    80

    /* 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

    83

     * 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

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     * remaining st code is being handled.

    87

     */

    88

    search_expression_type_c *search_expression_type;

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    search_varfb_instance_type_c *search_varfb_instance_type;

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    search_base_type_c search_base_type;

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    94

    symbol_c* current_array_type;

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    symbol_c* current_param_type;

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    97

    int fcall_number;

    98

    symbol_c *fbname;

    99

   100

    bool first_subrange_case_list;

   101

   102

    variablegeneration_t wanted_variablegeneration;

   103

    casegeneration_t wanted_casegeneration;

   104

   105

  public:

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    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);

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      this->set_variable_prefix(variable_prefix);

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      current_array_type = NULL;

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      current_param_type = NULL;

   114

      fcall_number = 0;

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      fbname = name;

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      wanted_variablegeneration = expression_vg;

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      wanted_casegeneration = none_cg;

   118

    }

   119

   120

    virtual ~generate_c_st_c(void) {

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      delete search_fb_instance_decl;

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      delete search_expression_type;

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      delete search_varfb_instance_type;

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    }

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   126

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  public:

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    void generate(statement_list_c *stl) {

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      stl->accept(*this);

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    }

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  private:

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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);

   143

  }

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  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("(");

   153

   154

  variablegeneration_t old_wanted_variablegeneration = wanted_variablegeneration;

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  wanted_variablegeneration = complextype_base_vg;

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  symbol->accept(*this);

   157

  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;

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  return NULL;

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}

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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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    }

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  }

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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);

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    else

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      s4o.print(SET_VAR);

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    s4o.print("(");

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  }

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   195

  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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  }

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  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

   210

   * the correct value regarding our 'symbol'.

   211

   */

   212

  search_varfb_instance_type->get_vartype(symbol);

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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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  }

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  s4o.print(")");

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  wanted_variablegeneration = expression_vg;

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  return NULL;

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}

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

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/* B 1.3.3 - Derived data types */

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

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/*  signed_integer DOTDOT signed_integer */

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void *visit(subrange_c *symbol) {

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  switch (wanted_casegeneration) {

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    case subrange_cg:

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      s4o.print("__case_expression >= ");

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

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      s4o.print(" && __case_expression <= ");

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

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      break;

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    default:

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      break;

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  }

   240

  return NULL;

   241

}

   242

   249

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

   250

/* B 1.4 - Variables */

   251

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

   252

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;

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  else if (this->is_variable_prefix_null()) {

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         vartype = search_varfb_instance_type->get_vartype(symbol);

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         if (wanted_variablegeneration == fparam_output_vg) {

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           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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         }

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  }

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  else

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      print_getter(symbol);

   271

  return NULL;

   272

}

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

   275

/* 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("*(");

   285

  }

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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:

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        s4o.print(GET_LOCATED_BY_REF);

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        s4o.print("(");

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        break;

   296

      default:

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        break;

   298

    }

   299

  }

   300

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

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   312

// 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);

   321

      s4o.print(".");

   322

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

   323

      break;

   324

    default:

   325

      if (this->is_variable_prefix_null()) {

   326

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

   327

    	s4o.print(".");

   328

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

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      }

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      else

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    	print_getter(symbol);

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      break;

   333

  }

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  return NULL;

   335

}

   336

   337

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

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//SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   339

void *visit(array_variable_c *symbol) {

   340

  switch (wanted_variablegeneration) {

   341

    case complextype_base_vg:

   342

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

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      break;

   344

    case complextype_suffix_vg:

   345

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

   346

   347

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

   348

      if (current_array_type == NULL) ERROR;

   349

   350

      s4o.print(".table");

   351

      wanted_variablegeneration = expression_vg;

   352

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

   353

      wanted_variablegeneration = complextype_suffix_vg;

   354

   355

      current_array_type = NULL;

   356

      break;

   357

    default:

   358

      if (this->is_variable_prefix_null()) {

   359

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

   360

   361

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

   362

    	if (current_array_type == NULL) ERROR;

   363

   364

    	s4o.print(".table");

   365

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

   366

   367

        current_array_type = NULL;

   368

      }

   369

      else

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    	print_getter(symbol);

   371

      break;

   372

  }

   373

  return NULL;

   374

}

   375

   376

/* subscript_list ',' subscript */

   377

void *visit(subscript_list_c *symbol) {

   379

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

   384

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

   387

    s4o.print(")]");

   388

  }

   390

  return NULL;

   391

}

   392

   393

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

   394

/* B 1.4.3 - Declaration & Initialisation */

   395

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

   396

   397

/* helper symbol for structure_initialization */

   398

/* structure_element_initialization_list ',' structure_element_initialization */

   399

void *visit(structure_element_initialization_list_c *symbol) {

   400

  generate_c_structure_initialization_c *structure_initialization = new generate_c_structure_initialization_c(&s4o);

   401

  structure_initialization->init_structure_default(this->current_param_type);

   402

  structure_initialization->init_structure_values(symbol);

   403

  delete structure_initialization;

   404

  return NULL;

   405

}

   406

   407

/* helper symbol for array_initialization */

   408

/* array_initial_elements_list ',' array_initial_elements */

   409

void *visit(array_initial_elements_list_c *symbol) {

   410

  generate_c_array_initialization_c *array_initialization = new generate_c_array_initialization_c(&s4o);

   411

  array_initialization->init_array_size(this->current_param_type);

   412

  array_initialization->init_array_values(symbol);

   413

  delete array_initialization;

   414

  return NULL;

   415

}

   416

   417

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

   418

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

   419

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

   420

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

   421

/* B 3.1 - Expressions */

   422

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

   423

void *visit(or_expression_c *symbol) {

   424

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

   425

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

   426

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

   427

      ERROR;

   428

  if (search_expression_type->is_bool_type(left_type))

   429

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

   430

  if (search_expression_type->is_binary_type(left_type))

   431

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

   432

  ERROR;

   433

  return NULL;

   434

}

   435

   436

void *visit(xor_expression_c *symbol) {

   437

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

   438

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

   439

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

   440

      ERROR;

   441

  if (search_expression_type->is_bool_type(left_type)) {

   442

    s4o.print("(");

   443

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

   444

    s4o.print(" && !");

   445

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

   446

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

   447

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

   448

    s4o.print(" && ");

   449

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

   450

    s4o.print(")");

   451

    return NULL;

   452

  }

   453

  if (search_expression_type->is_binary_type(left_type))

   454

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

   455

  ERROR;

   456

  return NULL;

   457

}

   458

   459

void *visit(and_expression_c *symbol) {

   460

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

   461

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

   462

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

   463

      ERROR;

   464

  if (search_expression_type->is_bool_type(left_type))

   465

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

   466

  if (search_expression_type->is_binary_type(left_type))

   467

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

   468

  ERROR;

   469

  return NULL;

   470

}

   471

   472

void *visit(equ_expression_c *symbol) {

   473

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

   474

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

   475

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

   476

      ERROR;

   477

  if (search_expression_type->is_time_type(left_type) ||

   478

      search_expression_type->is_string_type(left_type))

   479

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

   480

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

   481

}

   482

   483

void *visit(notequ_expression_c *symbol) {

   484

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

   485

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

   486

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

   487

      ERROR;

   488

  if (search_expression_type->is_time_type(left_type) ||

   489

      search_expression_type->is_string_type(left_type))

   490

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

   491

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

   492

}

   493

   494

void *visit(lt_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