diff -r 000000000000 -r fb772792efd1 stage4/generate_cc/function_param_iterator.cc --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/stage4/generate_cc/function_param_iterator.cc Wed Jan 31 15:32:38 2007 +0100 @@ -0,0 +1,426 @@ +/* + * (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) + * + */ + + +/* + * Function parameter iterator. + * Iterate through the in/out parameters of a function declaration. + * Function blocks are also suported. + * + * This is part of the 4th stage that generates + * a c++ source program equivalent to the IL and ST + * code. + */ + + + + + + +//#include /* required for NULL */ +//#include +//#include + +//#include "../../util/symtable.hh" + +//#include "generate_cc.hh" + + +#include "../../absyntax/visitor.hh" + + +/* given a function_declaration_c, iterate through each + * function in/out/inout parameter, returning the name + * of each parameter...function_param_iterator_c + */ +class function_param_iterator_c : public null_visitor_c { + public: + /* A type to specify the type of parameter. + * VAR_INPUT => direction_in + * VAR_OUTPUT => direction_out + * VAR_IN_OUT => direction_inout + * VAR_EXTERNAL => direction_extref + * + * Note that VAR_EXTERNAL declares variables that are in reality references + * to global variables. This is used only inside programs! + * These references to external variables must be correctly initialised to refer + * to the correct global variable. Note that the user may define which variable is to be + * referenced in a CONFIGURATION, and that different instantiations of a program + * may have the same external variable reference diffenrent global variables! + * The references must therefore be correctly initialised when the program instance + * is created. This may be done by the PROGRAM class constructor since the ST and IL + * languages do not allow the VAR_EXTERNAL reference to change at runtime + * for a specific instance. + * + * We therefore need to call a PROGRAM class constructor with the variables + * that should be refernced by the VAR_EXTERNAL variables. The direction_extref will + * be used to identify these parameters! + */ + typedef enum {direction_in, direction_out, direction_inout, direction_extref} param_direction_t ; + + + private: + /* a pointer to the function_block_declaration_c + * or function_declaration_c currently being analysed. + */ + symbol_c *f_decl; + int next_param, param_count; + identifier_c *current_param_name; + symbol_c *current_param_type; + symbol_c *current_param_default_value; + param_direction_t current_param_direction; + + private: + void* handle_param_list(list_c *list) { + if (next_param <= param_count + list->n) + return list->elements[next_param - param_count - 1]; + + /* the desired param is not on this list... */ + param_count += list->n; + return NULL; + } + + void* handle_single_param(symbol_c *var_name) { + param_count++; + if (next_param == param_count) + return var_name; + + /* not yet the desired param... */ + return NULL; + } + + void* iterate_list(list_c *list) { + void *res; + for (int i = 0; i < list->n; i++) { + res = list->elements[i]->accept(*this); + if (res != NULL) + return res; + } + return NULL; + } + + + public: + /* start off at the first parameter once again... */ + void reset(void) { + next_param = param_count = 0; + current_param_name = NULL; + current_param_type = current_param_default_value = NULL; + } + + /* initialise the iterator object. + * We must be given a reference to the function declaration + * that will be analysed... + */ + function_param_iterator_c(function_declaration_c *f_decl) { + this->f_decl = f_decl; + reset(); + } + + /* initialise the iterator object. + * We must be given a reference to the function block declaration + * that will be analysed... + */ + function_param_iterator_c(function_block_declaration_c *fb_decl) { + this->f_decl = fb_decl; + reset(); + } + + /* initialise the iterator object. + * We must be given a reference to the program declaration + * that will be analysed... + */ + function_param_iterator_c(program_declaration_c *p_decl) { + this->f_decl = p_decl; + reset(); + } + + /* Skip to the next parameter. After object creation, + * the object references on parameter _before_ the first, so + * this function must be called once to get the object to + * reference the first parameter... + * + * Returns the parameter's name! + */ + identifier_c *next(void) { + void *res; + param_count = 0; + next_param++; + res = f_decl->accept(*this); + if (res == NULL) + return NULL; + + symbol_c *sym = (symbol_c *)res; + identifier_c *identifier = dynamic_cast(sym); + if (identifier == NULL) + ERROR; + + current_param_name = identifier; + return current_param_name; + } + + /* Returns the currently referenced parameter's default value, + * or NULL if none is specified in the function declrataion itself. + */ + symbol_c *default_value(void) { + return current_param_default_value; + } + + /* Returns the currently referenced parameter's type name. */ + symbol_c *param_type(void) { + return current_param_type; + } + + /* Returns the currently referenced parameter's data passing direction. + * i.e. VAR_INPUT, VAR_OUTPUT or VAR_INOUT + */ + param_direction_t param_direction(void) { + return current_param_direction; + } + +/******************************************/ +/* B 1.4.3 - Declaration & Initialisation */ +/******************************************/ + void *visit(input_declarations_c *symbol) { + TRACE("input_declarations_c"); + current_param_direction = direction_in; + return symbol->input_declaration_list->accept(*this); + } + void *visit(input_declaration_list_c *symbol) {TRACE("input_declaration_list_c"); return iterate_list(symbol);} + void *visit(edge_declaration_c *symbol) {TRACE("edge_declaration_c"); return symbol->var1_list->accept(*this);} + +#if 0 +/* var1_list ':' array_spec_init */ +SYM_REF2(array_var_init_decl_c, var1_list, array_spec_init) + +/* var1_list ':' initialized_structure */ +SYM_REF2(structured_var_init_decl_c, var1_list, initialized_structure) + +/* name_list ':' function_block_type_name ASSIGN structure_initialization */ +/* structure_initialization -> may be NULL ! */ +SYM_REF4(fb_name_decl_c, fb_name_list, function_block_type_name, structure_initialization, unused) + +/* name_list ',' fb_name */ +SYM_LIST(fb_name_list_c) +#endif + + void *visit(output_declarations_c *symbol) { + TRACE("output_declarations_c"); + current_param_direction = direction_out; + return symbol->var_init_decl_list->accept(*this); + } + void *visit(input_output_declarations_c *symbol) { + TRACE("input_output_declarations_c"); + current_param_direction = direction_inout; + return symbol->var_declaration_list->accept(*this); + } + void *visit(var_declaration_list_c *symbol) {TRACE("var_declaration_list_c"); return iterate_list(symbol);} + +#if 0 +/* var1_list ':' array_specification */ +SYM_REF2(array_var_declaration_c, var1_list, array_specification) + +/* var1_list ':' structure_type_name */ +SYM_REF2(structured_var_declaration_c, var1_list, structure_type_name) +#endif + +/* VAR [CONSTANT] var_init_decl_list END_VAR */ + void *visit(var_declarations_c *symbol) {TRACE("var_declarations_c"); return NULL;} + +#if 0 +/* VAR RETAIN var_init_decl_list END_VAR */ +SYM_REF2(retentive_var_declarations_c, var_init_decl_list, unused) + +/* VAR [CONSTANT|RETAIN|NON_RETAIN] located_var_decl_list END_VAR */ +/* option -> may be NULL ! */ +SYM_REF2(located_var_declarations_c, option, located_var_decl_list) + +/* helper symbol for located_var_declarations */ +/* located_var_decl_list located_var_decl ';' */ +SYM_LIST(located_var_decl_list_c) + +/* [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) +#endif + +/*| VAR_EXTERNAL [CONSTANT] external_declaration_list END_VAR */ +/* option -> may be NULL ! */ +// SYM_REF2(external_var_declarations_c, option, external_declaration_list) + void *visit(external_var_declarations_c *symbol) { + TRACE("external_var_declarations_c"); + current_param_direction = direction_extref; + return symbol->external_declaration_list->accept(*this); + } + +/* helper symbol for external_var_declarations */ +/*| external_declaration_list external_declaration';' */ +// SYM_LIST(external_declaration_list_c) + void *visit(external_declaration_list_c *symbol) {TRACE("external_declaration_list_c"); return iterate_list(symbol);} + +/* 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) { + TRACE("external_declaration_c"); + /* It is OK to store these values in the current_param_XXX + * variables, because if the desired parameter is not in the + * variable list we will be analysing, the current_param_XXXX + * variables will get overwritten when we visit the next + * var1_init_decl_c list! + */ + current_param_default_value = spec_init_sperator_c::get_init(symbol->specification); + current_param_type = spec_init_sperator_c::get_spec(symbol->specification); + + return handle_single_param(symbol->global_var_name); + } + + +#if 0 +/*| VAR_GLOBAL [CONSTANT|RETAIN] global_var_decl_list END_VAR */ +/* option -> may be NULL ! */ +SYM_REF2(global_var_declarations_c, option, global_var_decl_list) + +/* helper symbol for global_var_declarations */ +/*| global_var_decl_list global_var_decl ';' */ +SYM_LIST(global_var_decl_list_c) + +/*| 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) + +/*| global_var_name location */ +SYM_REF2(global_var_spec_c, global_var_name, location) + +/* AT direct_variable */ +SYM_REF2(location_c, direct_variable, unused) + +/*| global_var_list ',' global_var_name */ +SYM_LIST(global_var_list_c) + +/* var1_list ':' single_byte_string_spec */ +SYM_REF2(single_byte_string_var_declaration_c, var1_list, single_byte_string_spec) + +/* 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) + +/* var1_list ':' double_byte_string_spec */ +SYM_REF2(double_byte_string_var_declaration_c, var1_list, double_byte_string_spec) + +/* 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) + +/*| VAR [RETAIN|NON_RETAIN] incompl_located_var_decl_list END_VAR */ +/* option ->may be NULL ! */ +SYM_REF2(incompl_located_var_declarations_c, option, incompl_located_var_decl_list) + +/* helper symbol for incompl_located_var_declarations */ +/*| incompl_located_var_decl_list incompl_located_var_decl ';' */ +SYM_LIST(incompl_located_var_decl_list_c) + +/* variable_name incompl_location ':' var_spec */ +SYM_REF4(incompl_located_var_decl_c, variable_name, incompl_location, var_spec, unused) + +/* AT incompl_location_token */ +SYM_TOKEN(incompl_location_c) +#endif + + + void *visit(var1_init_decl_c *symbol) { + TRACE("var1_init_decl_c"); + /* It is OK to store these values in the current_param_XXX + * variables, because if the desired parameter is not in the + * variable list we will be analysing, the current_param_XXXX + * variables will get overwritten when we visit the next + * var1_init_decl_c list! + */ + current_param_default_value = spec_init_sperator_c::get_init(symbol->spec_init); + current_param_type = spec_init_sperator_c::get_spec(symbol->spec_init); + + return symbol->var1_list->accept(*this); + } + + + + void *visit(var1_list_c *symbol) { + TRACE("var1_list_c"); + return handle_param_list(symbol); + } + + void *visit(var_init_decl_list_c *symbol) {TRACE("var_init_decl_list_c"); return iterate_list(symbol);} + + +/***********************/ +/* B 1.5.1 - Functions */ +/***********************/ + void *visit(function_declaration_c *symbol) {TRACE("function_declaration_c"); return symbol->var_declarations_list->accept(*this);} + /* intermediate helper symbol for function_declaration */ + void *visit(var_declarations_list_c *symbol) {TRACE("var_declarations_list_c"); return iterate_list(symbol);} + void *visit(function_var_decls_c *symbol) {TRACE("function_var_decls_c"); /* ignore */ return NULL;} + + +/*****************************/ +/* B 1.5.2 - Function Blocks */ +/*****************************/ +/* FUNCTION_BLOCK derived_function_block_name io_OR_other_var_declarations function_block_body END_FUNCTION_BLOCK */ + void *visit(function_block_declaration_c *symbol) {TRACE("function_block_declaration_c"); return symbol->var_declarations->accept(*this);} + +/* intermediate helper symbol for function_declaration */ +/* { io_var_declarations | other_var_declarations } */ +/* + * NOTE: we re-use the var_declarations_list_c + */ + +/* VAR_TEMP temp_var_decl_list END_VAR */ + void *visit(temp_var_decls_c *symbol) {TRACE("temp_var_decls_c"); /* ignore */ return NULL;} + void *visit(temp_var_decls_list_c *symbol) {TRACE("temp_var_decls_list_c"); /* ignore */ return NULL;} + +/* VAR NON_RETAIN var_init_decl_list END_VAR */ + void *visit(non_retentive_var_decls_c *symbol) {TRACE("non_retentive_var_decls_c"); /* ignore */ return NULL;} + + +/**********************/ +/* B 1.5.3 - Programs */ +/**********************/ +/* PROGRAM program_type_name program_var_declarations_list function_block_body END_PROGRAM */ +// SYM_REF4(program_declaration_c, program_type_name, var_declarations, function_block_body, unused) + void *visit(program_declaration_c *symbol) {TRACE("program_declaration_c"); return symbol->var_declarations->accept(*this);} + +/* intermediate helper symbol for program_declaration_c */ +/* { io_var_declarations | other_var_declarations } */ +/* + * NOTE: we re-use the var_declarations_list_c + */ + +}; + + + + + + +