diff -r 41cb5b80416e -r e1f0ebd2d9ec stage4/generate_cc/decompose_var_instance_name.cc --- a/stage4/generate_cc/decompose_var_instance_name.cc Tue Oct 23 10:35:58 2007 +0200 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,132 +0,0 @@ -/* - * (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) - * - */ - - -/* Decomposes a variable instance name into its constituents, - * example: - * window.points[1].coordinate.x - * - * will succesfully return - * - window - * - points - * - coordinate - * - x - * on succesive calls to decompose_var_instance_name_c::next_part() - */ -class decompose_var_instance_name_c: null_visitor_c { - - private: - symbol_c *variable_name; - symbol_c *next_variable_name; - symbol_c *current_recursive_variable_name; - symbol_c *previously_returned_variable_name; - - public: - decompose_var_instance_name_c(symbol_c *variable_instance_name) { - variable_name = variable_instance_name; - next_variable_name = NULL; - current_recursive_variable_name = NULL; - previously_returned_variable_name = NULL; - } - - public: - symbol_c *next_part(void) { - /* We must always start from the top! - * See note in the structured_variable_c visitor - * to understand why... - */ - symbol_c *res = (symbol_c *)variable_name->accept(*this); - next_variable_name = current_recursive_variable_name; - - if (previously_returned_variable_name == res) - return NULL; - previously_returned_variable_name = res; - return res; - } - - public: -/*********************/ -/* B 1.4 - Variables */ -/*********************/ - void *visit(symbolic_variable_c *symbol) {return (void *)(symbol->var_name);} - -/********************************************/ -/* B.1.4.1 Directly Represented Variables */ -/********************************************/ - void *visit(direct_variable_c *symbol) {return (void *)symbol;} - -/*************************************/ -/* B.1.4.2 Multi-element Variables */ -/*************************************/ -/* subscripted_variable '[' subscript_list ']' */ -// SYM_REF2(array_variable_c, subscripted_variable, subscript_list) - void *visit(array_variable_c *symbol) { - /* NOTE: the subscripted_variable may itself be a structure!, - * so we must recursevily visit! - */ - return symbol->subscripted_variable->accept(*this); - } - -/* record_variable '.' field_selector */ -/* WARNING: input and/or output variables of function blocks - * may be accessed as fields of a tructured variable! - * Code handling a structured_variable_c must take - * this into account! - */ -//SYM_REF2(structured_variable_c, record_variable, field_selector) - void *visit(structured_variable_c *symbol) { - /* NOTE: The following code will not work, as structured_variable_c - * are grouped on the left, and not on the right! - * - * example: window.origin.x - * will result in - * s1 = structured_variable_c("window, "origin"); - * s2 = structured_variable_c(s1, "x"); - * AND NOT - * s1 = structured_variable_c("origin", "x"); - * s2 = structured_variable_c("window", s1); - * - * as the following code assumes!! - * - current_variable_name = symbol->field_selector; - return symbol->record_variable->accept(*this); - */ - - /* The correct code, is therefore more complex... */ - if (next_variable_name == symbol) { - /* NOTE: field_selector is always an identifier_c, - * so we do not have to recursevily visit it again... - * return (void *)symbol->field_selector->accept(*this); -> NOT REQUIRED!! - */ - return (void *)symbol->field_selector; - } - - current_recursive_variable_name = symbol; - return symbol->record_variable->accept(*this); - } -}; - - - -