diff -r 000000000000 -r fb772792efd1 stage4/generate_cc/search_var_instance_decl.cc --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/stage4/generate_cc/search_var_instance_decl.cc Wed Jan 31 15:32:38 2007 +0100 @@ -0,0 +1,304 @@ +/* + * (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) + * + */ + +/* Determine the data type of a specific variable instance, including + * function block instances. + * A reference to the relevant variable declaration is returned. + * The variable instance may NOT be a member of a structure of a memeber + * of a structure of an element of an array of ... + * + * example: + * window.points[1].coordinate.x + * window.points[1].colour + * etc... ARE NOT ALLOWED! + * + * This class must only be passed the name of the variable that will appear + * in the variable declaration. In the above examples, this would be + * 'window' !! + * + * + * If you need to pass a complete name of a variable instance (such as + * 'window.points[1].coordinate.x') use the search_varfb_instance_type_c instead! + */ +/* Note that current_type_decl that this class returns may reference the + * name of a type, or the type declaration itself! + * For an example of the first, consider a variable declared as ... + * x : AAA; + * where the AAA type is previously declared as whatever. + * For an example of the second, consider a variable declared as ... + * x : array of int [10]; ----> is allowed + * + * If it is the first, we will return a reference to the name, if the second + * we return a reference to the declaration!! + */ +class search_var_instance_decl_c: public search_visitor_c { + + private: + symbol_c *search_scope; + symbol_c *search_name; + symbol_c *current_type_decl; + + public: + search_var_instance_decl_c(symbol_c *search_scope) { + this->search_scope = search_scope; + this->search_name = NULL; + this->current_type_decl = NULL; + } + + symbol_c *get_decl(symbol_c *variable_instance_name) { + this->search_name = variable_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 */ +/******************************************/ +/* edge -> The F_EDGE or R_EDGE directive */ +// SYM_REF2(edge_declaration_c, edge, var1_list) +// TODO + +/* var1_list is one of the following... + * simple_spec_init_c * + * subrange_spec_init_c * + * enumerated_spec_init_c * + */ +// SYM_REF2(var1_init_decl_c, var1_list, spec_init) + void *visit(var1_init_decl_c *symbol) { + current_type_decl = symbol->spec_init; + return symbol->var1_list->accept(*this); + } + +/* var1_list ',' variable_name */ +// SYM_LIST(var1_list_c) + void *visit(var1_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_type_decl should be != NULL */ + return current_type_decl; + } + return NULL; + } + +/* name_list ':' function_block_type_name ASSIGN structure_initialization */ +/* structure_initialization -> may be NULL ! */ + void *visit(fb_name_decl_c *symbol) { + current_type_decl = 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_type_decl; + } + return NULL; + } + +/* var1_list ':' array_spec_init */ +// SYM_REF2(array_var_init_decl_c, var1_list, array_spec_init) + void *visit(array_var_init_decl_c *symbol) { + current_type_decl = symbol->array_spec_init; + return symbol->var1_list->accept(*this); + } + +/* var1_list ':' initialized_structure */ +// SYM_REF2(structured_var_init_decl_c, var1_list, initialized_structure) + void *visit(structured_var_init_decl_c *symbol) { + current_type_decl = symbol->initialized_structure; + return symbol->var1_list->accept(*this); + } + +/* var1_list ':' array_specification */ +// SYM_REF2(array_var_declaration_c, var1_list, array_specification) + void *visit(array_var_declaration_c *symbol) { + current_type_decl = symbol->array_specification; + return symbol->var1_list->accept(*this); + } + +/* var1_list ':' structure_type_name */ +// SYM_REF2(structured_var_declaration_c, var1_list, structure_type_name) + void *visit(structured_var_declaration_c *symbol) { + current_type_decl = symbol->structure_type_name; + return symbol->var1_list->accept(*this); + } + +/* [variable_name] location ':' located_var_spec_init */ +/* variable_name -> may be NULL ! */ +// SYM_REF4(located_var_decl_c, variable_name, location, located_var_spec_init, unused) +// TODO!! + +/* global_var_name ':' (simple_specification|subrange_specification|enumerated_specification|array_specification|prev_declared_structure_type_name|function_block_type_name */ +// SYM_REF2(external_declaration_c, global_var_name, specification) + void *visit(external_declaration_c *symbol) { + if (compare_identifiers(symbol->global_var_name, search_name) == 0) + return symbol->specification; + return NULL; + } + +/*| global_var_spec ':' [located_var_spec_init|function_block_type_name] */ +/* type_specification ->may be NULL ! */ +// SYM_REF2(global_var_decl_c, global_var_spec, type_specification) +// TODO!! + +/*| global_var_name location */ +// SYM_REF2(global_var_spec_c, global_var_name, location) +// TODO!! + +/* AT direct_variable */ +// SYM_REF2(location_c, direct_variable, unused) +// TODO!! + +/*| global_var_list ',' global_var_name */ +// SYM_LIST(global_var_list_c) +// TODO!! + +/* var1_list ':' single_byte_string_spec */ +// SYM_REF2(single_byte_string_var_declaration_c, var1_list, single_byte_string_spec) + void *visit(single_byte_string_var_declaration_c *symbol) { + current_type_decl = symbol->single_byte_string_spec; + return symbol->var1_list->accept(*this); + } + +/* STRING ['[' integer ']'] [ASSIGN single_byte_character_string] */ +/* integer ->may be NULL ! */ +/* single_byte_character_string ->may be NULL ! */ +// SYM_REF2(single_byte_string_spec_c, integer, single_byte_character_string) +// TODO!! + +/* var1_list ':' double_byte_string_spec */ +// SYM_REF2(double_byte_string_var_declaration_c, var1_list, double_byte_string_spec) + void *visit(double_byte_string_var_declaration_c *symbol) { + current_type_decl = symbol->double_byte_string_spec; + return symbol->var1_list->accept(*this); + } + +/* WSTRING ['[' integer ']'] [ASSIGN double_byte_character_string] */ +/* integer ->may be NULL ! */ +/* double_byte_character_string ->may be NULL ! */ +// SYM_REF2(double_byte_string_spec_c, integer, double_byte_character_string) +// TODO!! + +/* variable_name incompl_location ':' var_spec */ +// SYM_REF4(incompl_located_var_decl_c, variable_name, incompl_location, var_spec, unused) +// TODO!! + +/* AT incompl_location_token */ +// SYM_TOKEN(incompl_location_c) +// TODO!! + + +/**************************************/ +/* B.1.5 - Program organization units */ +/**************************************/ +/***********************/ +/* B 1.5.1 - Functions */ +/***********************/ +// SYM_REF4(function_declaration_c, derived_function_name, type_name, var_declarations_list, function_body) + void *visit(function_declaration_c *symbol) { + /* functions have a variable named after themselves, to store + * the variable that will be returned!! + */ + if (compare_identifiers(symbol->derived_function_name, search_name) == 0) + return symbol->type_name; + + /* 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); + } + + +#if 0 +/*********************/ +/* B 1.4 - Variables */ +/*********************/ +SYM_REF2(symbolic_variable_c, var_name, unused) + +/********************************************/ +/* B.1.4.1 Directly Represented Variables */ +/********************************************/ +SYM_TOKEN(direct_variable_c) + +/*************************************/ +/* B.1.4.2 Multi-element Variables */ +/*************************************/ +/* subscripted_variable '[' subscript_list ']' */ +SYM_REF2(array_variable_c, subscripted_variable, subscript_list) + +/* subscript_list ',' subscript */ +SYM_LIST(subscript_list_c) + +/* 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) + + +#endif +}; + + + + +