diff -r 000000000000 -r fb772792efd1 stage4/generate_cc/search_fb_instance_decl.cc --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/stage4/generate_cc/search_fb_instance_decl.cc Wed Jan 31 15:32:38 2007 +0100 @@ -0,0 +1,141 @@ +/* + * (c) 2003 Mario de Sousa + * + * Offered to the public under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 of the + * License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General + * Public License for more details. + * + * This code is made available on the understanding that it will not be + * used in safety-critical situations without a full and competent review. + */ + +/* + * An IEC 61131-3 IL and ST compiler. + * + * Based on the + * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10) + * + */ + + +/* Returns the function block type declaration + * of a specific function block instance. + */ + + + +/* Returns the type name of a specific function block + * instance. This class will search the variable + * declarations inside the scope given to it + * searching for the declaration of the function + * block instance. + * + * The class constructor must be given the search scope + * (function, function block or program within which + * the function block instance was declared). + * + * This class will search the tree from the root given to the + * constructor. Another option would be to build a symbol table, + * and search that instead. Building the symbol table would be done + * while visiting the variable declaration objects in the parse + * tree. Unfortuantely, generate_cc_c does not visit these + * objects, delegating it to another class. This means that + * we would need another specialised class just to build the + * symbol table. We might just as well have a specialised class + * that searches the tree itself for the relevant info. This + * class is exactly that...! + */ +class search_fb_instance_decl_c: public search_visitor_c { + + private: + symbol_c *search_scope; + + symbol_c *search_name; + symbol_c *current_fb_type_name; + + public: + search_fb_instance_decl_c(symbol_c *search_scope) { + this->search_scope = search_scope; + this->current_fb_type_name = NULL; + } + + symbol_c *get_type_name(symbol_c *fb_instance_name) { + this->search_name = fb_instance_name; + return (symbol_c *)search_scope->accept(*this); + } + + public: +/***************************/ +/* B 0 - Programming Model */ +/***************************/ + void *visit(library_c *symbol) { + /* we do not want to search multiple declaration scopes, + * so we do not visit all the functions, fucntion blocks, etc... + */ + return NULL; + } + +/******************************************/ +/* B 1.4.3 - Declaration & Initialisation */ +/******************************************/ + +/* name_list ':' function_block_type_name ASSIGN structure_initialization */ +/* structure_initialization -> may be NULL ! */ + void *visit(fb_name_decl_c *symbol) { + current_fb_type_name = symbol->function_block_type_name; + return symbol->fb_name_list->accept(*this); + } + +/* name_list ',' fb_name */ + void *visit(fb_name_list_c *symbol) { + list_c *list = symbol; + for(int i = 0; i < list->n; i++) { + if (compare_identifiers(list->elements[i], search_name) == 0) + /* by now, current_fb_declaration should be != NULL */ + return current_fb_type_name; + } + return NULL; + } + +/**************************************/ +/* B.1.5 - Program organization units */ +/**************************************/ +/***********************/ +/* B 1.5.1 - Functions */ +/***********************/ + void *visit(function_declaration_c *symbol) { + /* no need to search through all the body, so we only + * visit the variable declarations...! + */ + return symbol->var_declarations_list->accept(*this); + } + +/*****************************/ +/* B 1.5.2 - Function Blocks */ +/*****************************/ + void *visit(function_block_declaration_c *symbol) { + /* no need to search through all the body, so we only + * visit the variable declarations...! + */ + return symbol->var_declarations->accept(*this); + } + +/**********************/ +/* B 1.5.3 - Programs */ +/**********************/ + void *visit(program_declaration_c *symbol) { + /* no need to search through all the body, so we only + * visit the variable declarations...! + */ + return symbol->var_declarations->accept(*this); + } +}; + + + +