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/*

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 * (c) 2003 Mario de Sousa

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 *

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 * Offered to the public under the terms of the GNU General Public License

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 * as published by the Free Software Foundation; either version 2 of the

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 * License, or (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, but

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 * WITHOUT ANY WARRANTY; without even the implied warranty of

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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General

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 * Public License for more details.

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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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/*

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 * An IEC 61131-3 IL and ST compiler.

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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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/* Determine the data type of a specific variable instance, including

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 * function block instances.

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 * A reference to the relevant variable declaration is returned.

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 * The variable instance may NOT be a member of a structure of a memeber

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 * of a structure of an element of an array of ...

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 *

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 * example:

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 *    window.points[1].coordinate.x

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 *    window.points[1].colour

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 *    etc... ARE NOT ALLOWED!

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 *

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 * This class must only be passed the name of the variable that will appear

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 * in the variable declaration. In the above examples, this would be

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 *   'window' !!

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 *

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 *

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 * If you need to pass a complete name of a variable instance (such as

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 * 'window.points[1].coordinate.x') use the search_varfb_instance_type_c instead!

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 */

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/* Note that current_type_decl that this class returns may reference the

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 * name of a type, or the type declaration itself!

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 * For an example of the first, consider a variable declared as ...

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 * x : AAA;

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 * where the AAA type is previously declared as whatever.

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 * For an example of the second, consider a variable declared as ...

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 * x : array of int [10];  ---->  is allowed

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 *

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 * If it is the first, we will return a reference to the name, if the second

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 * we return a reference to the declaration!!

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 */

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class search_var_instance_decl_c: public search_visitor_c {

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  private:

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    symbol_c *search_scope;

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    symbol_c *search_name;

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    symbol_c *current_type_decl;

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    /* variable used to store the type of variable currently being processed... */

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    /* Will contain a single value of generate_cc_vardecl_c::XXXX_vt */

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    unsigned int current_vartype;

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  public:

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    search_var_instance_decl_c(symbol_c *search_scope) {

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      this->current_vartype = none_vt;

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      this->search_scope = search_scope;

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      this->search_name = NULL;

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      this->current_type_decl = NULL;

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    }

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    symbol_c *get_decl(symbol_c *variable_instance_name) {

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      this->search_name = variable_instance_name;

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      return (symbol_c *)search_scope->accept(*this);

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    }

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    unsigned int get_vartype() {

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      return current_vartype;

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    }

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  public:

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    /* the types of variables that need to be processed... */

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    static const unsigned int none_vt   = 0x0000;

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    static const unsigned int input_vt    = 0x0001;  // VAR_INPUT

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    static const unsigned int output_vt   = 0x0002;  // VAR_OUTPUT

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    static const unsigned int inoutput_vt = 0x0004;  // VAR_IN_OUT

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    static const unsigned int private_vt  = 0x0008;  // VAR

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    static const unsigned int temp_vt   = 0x0010;  // VAR_TEMP

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    static const unsigned int external_vt = 0x0020;  // VAR_EXTERNAL

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    static const unsigned int located_vt  = 0x0080;  // VAR <var_name> AT <location>

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

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/* B 0 - Programming Model */

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

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    void *visit(library_c *symbol) {

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      /* we do not want to search multiple declaration scopes,

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       * so we do not visit all the functions, fucntion blocks, etc...

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       */

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      return NULL;

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    }

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

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/* B 1.4.3 - Declaration & Initialisation */

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

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/* edge -> The F_EDGE or R_EDGE directive */

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// SYM_REF2(edge_declaration_c, edge, var1_list)

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// TODO

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    void *visit(input_declarations_c *symbol) {

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      current_vartype = input_vt;

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      void *res = symbol->input_declaration_list->accept(*this);

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      if (res == NULL) {

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        current_vartype = none_vt;

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      }

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      return res;

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    }

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/* VAR_OUTPUT [RETAIN | NON_RETAIN] var_init_decl_list END_VAR */

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/* option -> may be NULL ! */

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    void *visit(output_declarations_c *symbol) {

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      current_vartype = output_vt;

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      void *res = symbol->var_init_decl_list->accept(*this);

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      if (res == NULL) {

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        current_vartype = none_vt;

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      }

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      return res;

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    }

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/*  VAR_IN_OUT var_declaration_list END_VAR */

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    void *visit(input_output_declarations_c *symbol) {

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      current_vartype = inoutput_vt;

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      void *res = symbol->var_declaration_list->accept(*this);

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      if (res == NULL) {

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        current_vartype = none_vt;

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      }

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      return res;

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    }

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/* VAR [CONSTANT] var_init_decl_list END_VAR */

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/* option -> may be NULL ! */

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/* helper symbol for input_declarations */

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    void *visit(var_declarations_c *symbol) {

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      current_vartype = private_vt;

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      void *res = symbol->var_init_decl_list->accept(*this);

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      if (res == NULL) {

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        current_vartype = none_vt;

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      }

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    }

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/*  VAR RETAIN var_init_decl_list END_VAR */

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    void *visit(retentive_var_declarations_c *symbol) {

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      current_vartype = private_vt;

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      void *res = symbol->var_init_decl_list->accept(*this);

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      if (res == NULL) {

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        current_vartype = none_vt;

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      }

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    }

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/*  VAR [CONSTANT|RETAIN|NON_RETAIN] located_var_decl_list END_VAR */

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/* option -> may be NULL ! */

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//SYM_REF2(located_var_declarations_c, option, located_var_decl_list)

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    void *visit(located_var_declarations_c *symbol) {

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      current_vartype = located_vt;

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      void *res = symbol->located_var_decl_list->accept(*this);

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      if (res == NULL) {

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        current_vartype = none_vt;

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      }

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    }

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/*| VAR_EXTERNAL [CONSTANT] external_declaration_list END_VAR */

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/* option -> may be NULL ! */

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//SYM_REF2(external_var_declarations_c, option, external_declaration_list)

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    void *visit(external_var_declarations_c *symbol) {

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      current_vartype = external_vt;

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      void *res = symbol->external_declaration_list->accept(*this);

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      if (res == NULL) {

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        current_vartype = none_vt;

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      }

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    }

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/* var1_list is one of the following...

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 *    simple_spec_init_c *

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 *    subrange_spec_init_c *

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 *    enumerated_spec_init_c *

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 */

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// SYM_REF2(var1_init_decl_c, var1_list, spec_init)

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    void *visit(var1_init_decl_c *symbol) {

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      current_type_decl = symbol->spec_init;

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      return symbol->var1_list->accept(*this);

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    }

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/* var1_list ',' variable_name */

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// SYM_LIST(var1_list_c)

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    void *visit(var1_list_c *symbol) {

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      list_c *list = symbol;

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

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        if (compare_identifiers(list->elements[i], search_name) == 0)

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	  /* by now, current_type_decl should be != NULL */

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          return current_type_decl;

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      }

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      return NULL;

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    }

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/* name_list ':' function_block_type_name ASSIGN structure_initialization */

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/* structure_initialization -> may be NULL ! */

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    void *visit(fb_name_decl_c *symbol) {

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      current_type_decl = symbol->function_block_type_name;

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      return symbol->fb_name_list->accept(*this);

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    }

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/* name_list ',' fb_name */

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    void *visit(fb_name_list_c *symbol) {

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      list_c *list = symbol;

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

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        if (compare_identifiers(list->elements[i], search_name) == 0)

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	  /* by now, current_fb_declaration should be != NULL */

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          return current_type_decl;

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      }

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      return NULL;

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    }

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/* var1_list ':' array_spec_init */

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// SYM_REF2(array_var_init_decl_c, var1_list, array_spec_init)

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    void *visit(array_var_init_decl_c *symbol) {

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      current_type_decl = symbol->array_spec_init;

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      return symbol->var1_list->accept(*this);

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    }

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/*  var1_list ':' initialized_structure */

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// SYM_REF2(structured_var_init_decl_c, var1_list, initialized_structure)

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    void *visit(structured_var_init_decl_c *symbol) {

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      current_type_decl = symbol->initialized_structure;

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      return symbol->var1_list->accept(*this);

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    }

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/*  var1_list ':' array_specification */

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// SYM_REF2(array_var_declaration_c, var1_list, array_specification)

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    void *visit(array_var_declaration_c *symbol) {

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      current_type_decl = symbol->array_specification;

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      return symbol->var1_list->accept(*this);

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    }

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/*  var1_list ':' structure_type_name */

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// SYM_REF2(structured_var_declaration_c, var1_list, structure_type_name)

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    void *visit(structured_var_declaration_c *symbol) {

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      current_type_decl = symbol->structure_type_name;

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      return symbol->var1_list->accept(*this);

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    }

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/*  [variable_name] location ':' located_var_spec_init */

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/* variable_name -> may be NULL ! */

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// SYM_REF4(located_var_decl_c, variable_name, location, located_var_spec_init, unused)

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// TODO!!

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/*  global_var_name ':' (simple_specification|subrange_specification|enumerated_specification|array_specification|prev_declared_structure_type_name|function_block_type_name */

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// SYM_REF2(external_declaration_c, global_var_name, specification)

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    void *visit(external_declaration_c *symbol) {

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      if (compare_identifiers(symbol->global_var_name, search_name) == 0)

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          return symbol->specification;

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      return NULL;

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    }

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/*| global_var_spec ':' [located_var_spec_init|function_block_type_name] */

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/* type_specification ->may be NULL ! */

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// SYM_REF2(global_var_decl_c, global_var_spec, type_specification)

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// TODO!!

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/*| global_var_name location */

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// SYM_REF2(global_var_spec_c, global_var_name, location)

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// TODO!!

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/*  AT direct_variable */

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// SYM_REF2(location_c, direct_variable, unused)

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// TODO!!

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/*| global_var_list ',' global_var_name */

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// SYM_LIST(global_var_list_c)

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// TODO!!

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/*  var1_list ':' single_byte_string_spec */

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// SYM_REF2(single_byte_string_var_declaration_c, var1_list, single_byte_string_spec)

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    void *visit(single_byte_string_var_declaration_c *symbol) {

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      current_type_decl = symbol->single_byte_string_spec;

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      return symbol->var1_list->accept(*this);

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    }

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/*  STRING ['[' integer ']'] [ASSIGN single_byte_character_string] */

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/* integer ->may be NULL ! */

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/* single_byte_character_string ->may be NULL ! */

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// SYM_REF2(single_byte_string_spec_c, integer, single_byte_character_string)

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// TODO!!

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/*  var1_list ':' double_byte_string_spec */

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// SYM_REF2(double_byte_string_var_declaration_c, var1_list, double_byte_string_spec)

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    void *visit(double_byte_string_var_declaration_c *symbol) {

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      current_type_decl = symbol->double_byte_string_spec;

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      return symbol->var1_list->accept(*this);

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    }

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/*  WSTRING ['[' integer ']'] [ASSIGN double_byte_character_string] */

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/* integer ->may be NULL ! */

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/* double_byte_character_string ->may be NULL ! */

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// SYM_REF2(double_byte_string_spec_c, integer, double_byte_character_string)

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// TODO!!

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/*  variable_name incompl_location ':' var_spec */

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// SYM_REF4(incompl_located_var_decl_c, variable_name, incompl_location, var_spec, unused)

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// TODO!!

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/*  AT incompl_location_token */

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// SYM_TOKEN(incompl_location_c)

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// TODO!!

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

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/* B.1.5 - Program organization units */

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

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

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/* B 1.5.1 - Functions */

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

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// SYM_REF4(function_declaration_c, derived_function_name, type_name, var_declarations_list, function_body)

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    void *visit(function_declaration_c *symbol) {

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      /* functions have a variable named after themselves, to store

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       * the variable that will be returned!!

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       */

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      if (compare_identifiers(symbol->derived_function_name, search_name) == 0)

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          return symbol->type_name;

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      /* no need to search through all the body, so we only

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       * visit the variable declarations...!

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       */

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      return symbol->var_declarations_list->accept(*this);

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    }

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

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/* B 1.5.2 - Function Blocks */

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

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    void *visit(function_block_declaration_c *symbol) {

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      /* no need to search through all the body, so we only

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       * visit the variable declarations...!

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       */

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      return symbol->var_declarations->accept(*this);

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    }

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

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/* B 1.5.3 - Programs */

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

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    void *visit(program_declaration_c *symbol) {

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      /* no need to search through all the body, so we only

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       * visit the variable declarations...!

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       */

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      return symbol->var_declarations->accept(*this);

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    }

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#if 0

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

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/* B 1.4 - Variables */

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

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SYM_REF2(symbolic_variable_c, var_name, unused)

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

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/* B.1.4.1   Directly Represented Variables */

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

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SYM_TOKEN(direct_variable_c)

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

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/* B.1.4.2   Multi-element Variables */

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

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

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SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

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/* subscript_list ',' subscript */

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SYM_LIST(subscript_list_c)

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/*  record_variable '.' field_selector */

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/*  WARNING: input and/or output variables of function blocks

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 *           may be accessed as fields of a tructured variable!

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 *           Code handling a structured_variable_c must take

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 *           this into account!

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 */

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SYM_REF2(structured_variable_c, record_variable, field_selector)

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#endif

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};

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