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

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

    42

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

    43

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

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

    45

    46

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class generate_c_st_c: public generate_c_base_c {

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  public:

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    typedef enum {

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      expression_vg,

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      complextype_base_vg,

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      complextype_suffix_vg,

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      fparam_output_vg

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    } variablegeneration_t;

    56

    57

    typedef enum {

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      single_cg,

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      subrange_cg,

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      none_cg

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    } casegeneration_t;

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  private:

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    /* 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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     */

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    search_fb_instance_decl_c    *search_fb_instance_decl;

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    search_varfb_instance_type_c *search_varfb_instance_type;

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    search_var_instance_decl_c   *search_var_instance_decl;

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    81

    symbol_c *scope_;

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    83

    symbol_c* current_array_type;

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    symbol_c* current_param_type;

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    86

    int fcall_number;

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    symbol_c *fbname;

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    bool first_subrange_case_list;

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    variablegeneration_t wanted_variablegeneration;

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    casegeneration_t wanted_casegeneration;

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  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_base_c(s4o_ptr) {

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      search_fb_instance_decl    = new search_fb_instance_decl_c   (scope);

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      search_varfb_instance_type = new search_varfb_instance_type_c(scope);

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      search_var_instance_decl   = new search_var_instance_decl_c  (scope);

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      scope_ = scope;

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   102

      this->set_variable_prefix(variable_prefix);

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      current_array_type = NULL;

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      current_param_type = NULL;

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      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;

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    }

   110

   111

    virtual ~generate_c_st_c(void) {

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      delete search_fb_instance_decl;

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      delete search_varfb_instance_type;

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      delete search_var_instance_decl;

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    }

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   117

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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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   123

  private:

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void *print_getter(symbol_c *symbol) {

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  unsigned int vartype = analyse_variable_c::first_nonfb_vardecltype(symbol, scope_);

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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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      if (!get_datatype_info_c::is_type_valid    (symbol->datatype)) ERROR;

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      if ( get_datatype_info_c::is_function_block(symbol->datatype))

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        s4o.print(GET_EXTERNAL_FB_BY_REF);

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      else

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        s4o.print(GET_EXTERNAL_BY_REF);

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    }

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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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  }

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  else {

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    if (vartype == search_var_instance_decl_c::external_vt) {

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      if (!get_datatype_info_c::is_type_valid    (symbol->datatype)) ERROR;

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      if ( get_datatype_info_c::is_function_block(symbol->datatype))

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        s4o.print(GET_EXTERNAL_FB);

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      else

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        s4o.print(GET_EXTERNAL);

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    }

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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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  }

   158

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  variablegeneration_t old_wanted_variablegeneration = wanted_variablegeneration;

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  s4o.print("(");

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  print_variable_prefix();  

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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 = 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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  if (fb_symbol == NULL) {

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    unsigned int vartype = analyse_variable_c::first_nonfb_vardecltype(symbol, scope_);

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    symbol_c *first_nonfb = analyse_variable_c::find_first_nonfb(symbol);

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    if (first_nonfb == NULL) ERROR;

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    if (vartype == search_var_instance_decl_c::external_vt) {

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      if (!get_datatype_info_c::is_type_valid    (first_nonfb->datatype)) ERROR;

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      if ( get_datatype_info_c::is_function_block(first_nonfb->datatype)) // handle situation where we are copying a complete fb -> fb1.fb2.fb3 := fb4 (and fb3 is external!)

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        s4o.print(SET_EXTERNAL_FB);

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      else

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        s4o.print(SET_EXTERNAL);

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    }

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    else 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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  }

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  else {

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    unsigned int vartype = search_var_instance_decl->get_vartype(fb_symbol);

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    if (vartype == search_var_instance_decl_c::external_vt)

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      s4o.print(SET_EXTERNAL_FB);

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    else

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      s4o.print(SET_VAR);

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  }

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  s4o.print("(");

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  if (fb_symbol != NULL) {

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    print_variable_prefix();

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    // It is my (MJS) conviction that by this time the following will always be true...

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    //   wanted_variablegeneration == expression_vg;

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    fb_symbol->accept(*this);

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    s4o.print(".,");

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    symbol->accept(*this);

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    s4o.print(",");

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    s4o.print(",");    

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  } else {

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    print_variable_prefix();

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    s4o.print(",");    

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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 = complextype_suffix_vg;

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    symbol->accept(*this);

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    s4o.print(",");

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  }

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  wanted_variablegeneration = expression_vg;

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  print_check_function(type, value, fb_value);

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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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   235

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

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      break;

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  }

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  return NULL;

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}

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/* ARRAY '[' array_subrange_list ']' OF non_generic_type_name */

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void *visit(array_specification_c *symbol) {

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

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  return NULL;

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}

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/*  enumerated_type_name ':' enumerated_spec_init */

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void *visit(enumerated_type_declaration_c *symbol) {

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

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  return NULL;

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}

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

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/* B 1.4 - Variables */

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

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void *visit(symbolic_variable_c *symbol) {

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  switch (wanted_variablegeneration) {

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    case complextype_base_vg:

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      symbol->var_name->accept(*this); //generate_c_base_c::visit(symbol);

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      break;

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    case complextype_suffix_vg:

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      break;

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    default:

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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("&(");

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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);

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      break;

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  }

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  return NULL;

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}

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

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/* 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("*(");

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  }

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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;

   313

      default:

   314

        break;

   315

    }

   316

  }

   317

  this->print_variable_prefix();

   318

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

   319

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

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      (!this->is_variable_prefix_null() && (wanted_variablegeneration == expression_vg   )) ||

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

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    s4o.print(")");

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  return NULL;

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}

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   326

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

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/* B.1.4.2   Multi-element Variables */

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

   329

   330

// 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);

   336

      /* NOTE: The following test includes a special case for SFC Steps. They are currently mapped onto a C data structure

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       *        that does not follow the standard IEC_<typename> pattern used for user defined structure datatypes 

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       *        (i.e. it does not include the 'values' and 'flag' structure 

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       *        elements that are tested by __GET_VAR and __SET_VAR acessor macros defined in acessor.h). However, the

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       *        STEP.T and STEP.X elements of this step structure are of the IEC_BOOL and IEC_TIME datatypes, and are 

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       *        actually structures that do have the 'value' and 'flags' elements. So, it is safe to say that any  variable

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       *        that is a STEPname is not of a complex type, as its .T and .X elements are and can later be safely accessed

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       *        using the __SET_VAR and __GET_VAR macros.

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       * 

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       *        For the above reason, a STEP must be handled as a FB, i.e. it does NOT contain the 'flags' and 'value' elements!

   346

       */

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      if (   get_datatype_info_c::is_function_block(symbol->record_variable->datatype)

   348

          || get_datatype_info_c::is_sfc_step      (symbol->record_variable->datatype)) {

   349

        if (NULL == symbol->record_variable->scope) ERROR;

   350

        search_var_instance_decl_c search_var_instance_decl(symbol->record_variable->scope);

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        else  

   356

          s4o.print(".");

   357

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

   358

      }

   359

      break;

   360

    case complextype_suffix_vg:

   361

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

   362

      // the following condition MUST be a negation of the above condition used in the 'case complextype_base_vg:'

   363

      if (!(   get_datatype_info_c::is_function_block(symbol->record_variable->datatype)     // if the record variable is not a FB... 

   364

            || get_datatype_info_c::is_sfc_step      (symbol->record_variable->datatype))) { // ...nor an SFC step name, then it will certainly be a structure!

   369

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

   370

      }

   371

      break;

   372

    default:

   373

      if (this->is_variable_prefix_null()) {

   381

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

   382

        s4o.print(".");

   383

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

   384

      }

   385

      else

   386

        print_getter(symbol);

   387

      break;

   388

  }

   389

  return NULL;

   390

}

   391

   392

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

   393

//SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   394

void *visit(array_variable_c *symbol) {

   395

  switch (wanted_variablegeneration) {

   396

    case complextype_base_vg:

   397

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

   398

      break;

   399

    case complextype_suffix_vg:

   400

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

   401

   402

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

   403

      if (current_array_type == NULL) ERROR;

   404

   405

      s4o.print(".table");

   406

      wanted_variablegeneration = expression_vg;

   407

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

   408

      wanted_variablegeneration = complextype_suffix_vg;

   409

   410

      current_array_type = NULL;

   411

      break;

   412

    default:

   413

      if (this->is_variable_prefix_null()) {

   414

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

   415

   416

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

   417

        if (current_array_type == NULL) ERROR;

   418

   419

        s4o.print(".table");

   420

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

   421

   422

        current_array_type = NULL;

   423

      }

   424

      else

   425

        print_getter(symbol);

   426

      break;

   427

  }

   428

  return NULL;

   429

}

   430

   431

/* subscript_list ',' subscript */

   432

void *visit(subscript_list_c *symbol) {

   433

  array_dimension_iterator_c* array_dimension_iterator = new array_dimension_iterator_c(current_array_type);

   434

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

   435

    symbol_c* dimension = array_dimension_iterator->next();

   436

    if (dimension == NULL) ERROR;

   437

   438

    s4o.print("[(");

   439

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

   440

    s4o.print(") - (");

   441

    dimension->accept(*this);

   442

    s4o.print(")]");

   443

  }

   444

  delete array_dimension_iterator;

   445

  return NULL;

   446

}

   447

   448

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

   449

/* B 1.4.3 - Declaration & Initialisation */

   450

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

   451

   452

/* helper symbol for structure_initialization */

   453

/* structure_element_initialization_list ',' structure_element_initialization */

   454

void *visit(structure_element_initialization_list_c *symbol) {

   455

  generate_c_structure_initialization_c *structure_initialization = new generate_c_structure_initialization_c(&s4o);

   456

  structure_initialization->init_structure_default(this->current_param_type);

   457

  structure_initialization->init_structure_values(symbol);

   458

  delete structure_initialization;

   459

  return NULL;

   460

}

   461

   462

/* helper symbol for array_initialization */

   463

/* array_initial_elements_list ',' array_initial_elements */

   464

void *visit(array_initial_elements_list_c *symbol) {

   465

  generate_c_array_initialization_c *array_initialization = new generate_c_array_initialization_c(&s4o);

   466

  array_initialization->init_array_size(this->current_param_type);

   467

  array_initialization->init_array_values(symbol);

   468

  delete array_initialization;

   469

  return NULL;

   470

}

   471

   472

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

   473

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

   474

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

   475

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

   476

/* B 3.1 - Expressions */

   477

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