improve performance of some extensible Standard Functions (ADD, MUL, AND, OR, XOR) -- Add comments!!
/*
* matiec - a compiler for the programming languages defined in IEC 61131-3
*
* Copyright (C) 2003-2011 Mario de Sousa (msousa@fe.up.pt)
* Copyright (C) 2007-2011 Laurent Bessard and Edouard Tisserant
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*
* 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 compiler.
*
* Based on the
* FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
*
*/
#include "absyntax_utils.hh"
/* 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_c_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...!
*/
search_fb_instance_decl_c::search_fb_instance_decl_c(symbol_c *search_scope) {
this->search_scope = search_scope;
this->current_fb_type_name = NULL;
}
symbol_c *search_fb_instance_decl_c::get_type_name(symbol_c *fb_instance_name) {
this->search_name = fb_instance_name;
return (symbol_c *)search_scope->accept(*this);
}
/***************************/
/* B 0 - Programming Model */
/***************************/
void *search_fb_instance_decl_c::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 *search_fb_instance_decl_c::visit(fb_name_decl_c *symbol) {
current_fb_type_name = spec_init_sperator_c::get_spec(symbol->fb_spec_init);
return symbol->fb_name_list->accept(*this);
}
/* name_list ',' fb_name */
void *search_fb_instance_decl_c::visit(fb_name_list_c *symbol) {
list_c *list = symbol;
for(int i = 0; i < list->n; i++) {
if (compare_identifiers(list->get_element(i), search_name) == 0)
/* by now, current_fb_declaration should be != NULL */
return current_fb_type_name;
}
return NULL;
}
/* name_list ',' fb_name */
void *search_fb_instance_decl_c::visit(external_declaration_c *symbol) {
if (compare_identifiers(symbol->global_var_name, search_name) == 0)
return spec_init_sperator_c::get_spec(symbol->specification);
return NULL;
}
/**************************************/
/* B.1.5 - Program organization units */
/**************************************/
/***********************/
/* B 1.5.1 - Functions */
/***********************/
void *search_fb_instance_decl_c::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 *search_fb_instance_decl_c::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 *search_fb_instance_decl_c::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);
}