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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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/* Returns the function block type declaration

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 * of a specific function block instance.

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 */

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/* Returns the type name of a specific function block

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 * instance. This class will search the variable

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 * declarations inside the scope given to it

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 * searching for the declaration of the function

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 * block instance.

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 *

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 * The class constructor must be given the search scope

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 * (function, function block or program within which

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 * the function block instance was declared).

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 *

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 * This class will search the tree from the root given to the

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 * constructor. Another option would be to build a symbol table,

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 * and search that instead. Building the symbol table would be done

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 * while visiting the variable declaration objects in the parse

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 * tree. Unfortuantely, generate_cc_c does not visit these

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 * objects, delegating it to another class. This means that

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 * we would need another specialised class just to build the

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 * symbol table. We might just as well have a specialised class

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 * that searches the tree itself for the relevant info. This

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 * class is exactly that...!

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 */

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class search_fb_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_fb_type_name;

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  public:

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    search_fb_instance_decl_c(symbol_c *search_scope) {

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      this->search_scope = search_scope;

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      this->current_fb_type_name = NULL;

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    }

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    symbol_c *get_type_name(symbol_c *fb_instance_name) {

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      this->search_name = fb_instance_name;

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

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    }

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  public:

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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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/* 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_fb_type_name = 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_fb_type_name;

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      }

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      return NULL;

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    }

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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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    void *visit(function_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_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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};

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