--- /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 <stdio.h> /* required for NULL */
+//#include <string>
+//#include <iostream>
+
+//#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<identifier_c *>(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
+ */
+
+};
+
+
+
+
+
+
+