/*
* (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 call parameter iterator.
* It will iterate through the formal parameters of a function call
* (i.e. function calls using the foo(<param1>, <param2>, ...) syntax).
* and/or search through the non-formal parameters of a function call
* (i.e. function calls using the foo(<name1> = <param1>, <name2> = <param2>, ...) syntax).
*
* Calls to function blocks and programs are also supported.
*
* 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_c.hh"
#include "../../absyntax/visitor.hh"
/*
* Function call parameter iterator.
* It will iterate through the formal parameters of a function call
* (i.e. function calls using the foo(<param1>, <param2>, ...) syntax).
* and/or search through the non-formal parameters of a function call
* (i.e. function calls using the foo(<name1> = <param1>, <name2> = <param2>, ...) syntax).
*
* Calls to function blocks and programs are also supported.
*
* Note that calls to next() will only iterate through formal parameters,
* and calls to search() will only serach through non-formal parameters.
*/
class function_call_param_iterator_c : public null_visitor_c {
private:
/* a pointer to the function call
* (or function block or program call!)
*/
symbol_c *f_call;
int next_param, param_count;
identifier_c *search_param_name;
/* Which operation of the class was called...
* Search a parameter, or iterate to the next parameter.
*/
typedef enum {iterate_op, search_op} operation_t;
operation_t current_operation;
private:
void *search_list(list_c *list) {
switch (current_operation) {
case iterate_op:
for(int i = 0; i < list->n; i++) {
void *res = list->elements[i]->accept(*this);
if (NULL != res) {
/* It went through the handle_parameter_assignment() function,
* and is therefore a parameter assignment (<param> = <value>),
* and not a simple expression (<value>).
*/
/* we do nothing... */
} else {
param_count++;
if (param_count == next_param) {
return list->elements[i];
}
}
}
return NULL;
break;
case search_op:
for(int i = 0; i < list->n; i++) {
void *res = list->elements[i]->accept(*this);
if (res != NULL)
return res;
}
return NULL;
break;
} /* switch */
return NULL;
}
void *handle_parameter_assignment(symbol_c *variable_name, symbol_c *expression) {
switch (current_operation) {
case iterate_op:
/* UGLY HACK -> this will be detected in the search_list() function */
return (void *)this; /* anything, as long as it is not NULL!! */
break;
case search_op:
identifier_c *variable_name2 = dynamic_cast<identifier_c *>(variable_name);
if (variable_name2 == NULL) ERROR;
if (strcasecmp(search_param_name->value, variable_name2->value) == 0)
/* FOUND! This is the same parameter!! */
return (void *)expression;
return NULL;
break;
}
ERROR;
return NULL;
}
public:
/* start off at the first parameter once again... */
void reset(void) {
next_param = param_count = 0;
}
/* initialise the iterator object.
* We must be given a reference to the function/program/function block call
* that will be analysed...
*/
function_call_param_iterator_c(symbol_c *f_call) {
/* It is expected that f_call will reference one of the following:
* program_configuration_c
* function_invocation_c
* fb_invocation_c
* il_function_call_c
* il_formal_funct_call_c
* ... (have I missed any?)
*/
this->f_call = f_call;
search_param_name = NULL;
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 whatever is being passed to the parameter!
*/
symbol_c *next(void) {
param_count = 0;
next_param++;
current_operation = function_call_param_iterator_c::iterate_op;
void *res = f_call->accept(*this);
return (symbol_c *)res;
}
/* Search for the value passed to the parameter named <param_name>... */
symbol_c *search(symbol_c *param_name) {
if (NULL == param_name) ERROR;
search_param_name = dynamic_cast<identifier_c *>(param_name);
if (NULL == search_param_name) ERROR;
current_operation = function_call_param_iterator_c::search_op;
void *res = f_call->accept(*this);
return (symbol_c *)res;
}
private:
/********************************/
/* B 1.7 Configuration elements */
/********************************/
/*
CONFIGURATION configuration_name
optional_global_var_declarations
(resource_declaration_list | single_resource_declaration)
optional_access_declarations
optional_instance_specific_initializations
END_CONFIGURATION
*/
/*
SYM_REF6(configuration_declaration_c, configuration_name, global_var_declarations, resource_declarations, access_declarations, instance_specific_initializations, unused)
*/
/* helper symbol for configuration_declaration */
/*
SYM_LIST(resource_declaration_list_c)
*/
/*
RESOURCE resource_name ON resource_type_name
optional_global_var_declarations
single_resource_declaration
END_RESOURCE
*/
/*
SYM_REF4(resource_declaration_c, resource_name, resource_type_name, global_var_declarations, resource_declaration)
*/
/* task_configuration_list program_configuration_list */
/*
SYM_REF2(single_resource_declaration_c, task_configuration_list, program_configuration_list)
*/
/* helper symbol for single_resource_declaration */
/*
SYM_LIST(task_configuration_list_c)
*/
/* helper symbol for single_resource_declaration */
/*
SYM_LIST(program_configuration_list_c)
*/
/* helper symbol for
* - access_path
* - instance_specific_init
*/
/*
SYM_LIST(any_fb_name_list_c)
*/
/* [resource_name '.'] global_var_name ['.' structure_element_name] */
/*
SYM_REF4(global_var_reference_c, resource_name, global_var_name, structure_element_name, unused)
*/
/* prev_declared_program_name '.' symbolic_variable */
/*
SYM_REF2(program_output_reference_c, program_name, symbolic_variable)
*/
/* TASK task_name task_initialization */
/*
SYM_REF2(task_configuration_c, task_name, task_initialization)
*/
/* '(' [SINGLE ASSIGN data_source ','] [INTERVAL ASSIGN data_source ','] PRIORITY ASSIGN integer ')' */
/*
SYM_REF4(task_initialization_c, single_data_source, interval_data_source, priority_data_source, unused)
*/
/* PROGRAM [RETAIN | NON_RETAIN] program_name [WITH task_name] ':' program_type_name ['(' prog_conf_elements ')'] */
// SYM_REF6(program_configuration_c, retain_option, program_name, task_name, program_type_name, prog_conf_elements, unused)
void *visit(program_configuration_c *symbol) {
TRACE("program_configuration_c");
return symbol->prog_conf_elements->accept(*this);
}
/* prog_conf_elements ',' prog_conf_element */
// SYM_LIST(prog_conf_elements_c)
void *visit(prog_conf_elements_c *symbol) {
TRACE("prog_conf_elements_c");
return search_list(symbol);
}
/* fb_name WITH task_name */
/*
SYM_REF2(fb_task_c, fb_name, task_name)
*/
/* any_symbolic_variable ASSIGN prog_data_source */
// SYM_REF2(prog_cnxn_assign_c, symbolic_variable, prog_data_source)
void *visit(prog_cnxn_assign_c *symbol) {
TRACE("prog_cnxn_assign_c");
/* NOTE: symbolic_variable may be something other than a symbolic_variable_c, but I (Mario)
* do not understand the semantics that should be implmeneted if it is not a
* symbolic_variable, so for the moment we simply give up!
*/
symbolic_variable_c *symb_var = dynamic_cast<symbolic_variable_c *>(symbol->symbolic_variable);
if (NULL == symb_var)
ERROR;
return handle_parameter_assignment(symb_var->var_name, symbol->prog_data_source);
}
/* any_symbolic_variable SENDTO data_sink */
// SYM_REF2(prog_cnxn_sendto_c, symbolic_variable, prog_data_source)
void *visit(prog_cnxn_sendto_c *symbol) {
TRACE("prog_cnxn_sendto_c");
/* NOTE: symbolic_variable may be something other than a symbolic_variable_c, but I (Mario)
* do not understand the semantics that should be implmeneted if it is not a
* symbolic_variable, so for the moment we simply give up!
*/
symbolic_variable_c *symb_var = dynamic_cast<symbolic_variable_c *>(symbol->symbolic_variable);
if (NULL == symb_var)
ERROR;
return handle_parameter_assignment(symb_var->var_name, symbol->data_sink);
}
/* VAR_CONFIG instance_specific_init_list END_VAR */
/*
SYM_REF2(instance_specific_initializations_c, instance_specific_init_list, unused)
*/
/* helper symbol for instance_specific_initializations */
/*
SYM_LIST(instance_specific_init_list_c)
*/
/* resource_name '.' program_name '.' {fb_name '.'}
((variable_name [location] ':' located_var_spec_init) | (fb_name ':' fb_initialization))
*/
/*
SYM_REF6(instance_specific_init_c, resource_name, program_name, any_fb_name_list, variable_name, location, initialization)
*/
/* helper symbol for instance_specific_init */
/* function_block_type_name ':=' structure_initialization */
/*
SYM_REF2(fb_initialization_c, function_block_type_name, structure_initialization)
*/
/****************************************/
/* B.2 - Language IL (Instruction List) */
/****************************************/
/***********************************/
/* B 2.1 Instructions and Operands */
/***********************************/
/* | function_name [il_operand_list] */
// SYM_REF2(il_function_call_c, function_name, il_operand_list)
void *visit(il_function_call_c *symbol) {
TRACE("il_function_call_c");
if (NULL != symbol->il_operand_list)
return symbol->il_operand_list->accept(*this);
return NULL;
}
/* | function_name '(' eol_list [il_param_list] ')' */
// SYM_REF2(il_formal_funct_call_c, function_name, il_param_list)
void *visit(il_formal_funct_call_c *symbol) {
TRACE("il_formal_funct_call_c");
if (NULL != symbol->il_param_list)
return symbol->il_param_list->accept(*this);
return NULL;
}
/* il_call_operator prev_declared_fb_name
* | il_call_operator prev_declared_fb_name '(' ')'
* | il_call_operator prev_declared_fb_name '(' eol_list ')'
* | il_call_operator prev_declared_fb_name '(' il_operand_list ')'
* | il_call_operator prev_declared_fb_name '(' eol_list il_param_list ')'
*/
// SYM_REF4(il_fb_call_c, il_call_operator, fb_name, il_operand_list, il_param_list)
void *visit(il_fb_call_c *symbol) {
TRACE("il_fb_call_c");
/* the following should never occur. In reality the syntax parser
* will guarantee that they never occur, but it makes it easier to
* understand the remaining code :-)
*/
//if ((NULL == symbol->il_operand_list) && (NULL == symbol->il_param_list)) ERROR;
//if ((NULL != symbol->il_operand_list) && (NULL != symbol->il_param_list)) ERROR;
if (NULL != symbol->il_operand_list)
return symbol->il_operand_list->accept(*this);
if (NULL != symbol->il_param_list)
return symbol->il_param_list->accept(*this);
return NULL;
}
/* | il_operand_list ',' il_operand */
// SYM_LIST(il_operand_list_c)
void *visit(il_operand_list_c *symbol) {
TRACE("il_operand_list_c");
return search_list(symbol);
}
/* | il_initial_param_list il_param_instruction */
// SYM_LIST(il_param_list_c)
void *visit(il_param_list_c *symbol) {
TRACE("il_param_list_c");
return search_list(symbol);
}
/* il_assign_operator il_operand
* | il_assign_operator '(' eol_list simple_instr_list ')'
*/
// SYM_REF4(il_param_assignment_c, il_assign_operator, il_operand, simple_instr_list, unused)
void *visit(il_param_assignment_c *symbol) {
TRACE("il_param_assignment_c");
// TODO : We do not yet handle a instruction list passed as parameter !!!
// since we do not yet support it, it is best to simply stop than to fail silently...
if (NULL != symbol->simple_instr_list) ERROR;
return handle_parameter_assignment(symbol->il_assign_operator, symbol->il_operand);
}
/* il_assign_out_operator variable */
// SYM_REF2(il_param_out_assignment_c, il_assign_out_operator, variable);
void *visit(il_param_out_assignment_c *symbol) {
TRACE("il_param_out_assignment_c");
return handle_parameter_assignment((symbol_c *)symbol->il_assign_out_operator->accept(*this), symbol->variable);
}
/*******************/
/* B 2.2 Operators */
/*******************/
/*| [NOT] any_identifier SENDTO */
// SYM_REF2(il_assign_out_operator_c, option, variable_name)
void *visit(il_assign_out_operator_c *symbol) {
TRACE("il_assign_out_operator_c");
// TODO : Handle not_param !!!
// we do not yet support it, so it is best to simply stop than to fail silently...
if (NULL != symbol->option) ERROR;
return (void *)symbol->variable_name;
}
/***************************************/
/* B.3 - Language ST (Structured Text) */
/***************************************/
/***********************/
/* B 3.1 - Expressions */
/***********************/
/*
SYM_REF2(function_invocation_c, function_name, parameter_assignment_list)
*/
void *visit(function_invocation_c *symbol) {
TRACE("function_invocation_c");
if ((symbol_c *)symbol == f_call && symbol->parameter_assignment_list != NULL)
return symbol->parameter_assignment_list->accept(*this);
else
return NULL;
}
/********************/
/* B 3.2 Statements */
/********************/
/*********************************/
/* B 3.2.1 Assignment Statements */
/*********************************/
/*
SYM_REF2(assignment_statement_c, l_exp, r_exp)
*/
/*****************************************/
/* B 3.2.2 Subprogram Control Statements */
/*****************************************/
/* RETURN */
// SYM_REF0(return_statement_c)
/* fb_name '(' [param_assignment_list] ')' */
/* param_assignment_list -> may be NULL ! */
// SYM_REF2(fb_invocation_c, fb_name, param_assignment_list)
void *visit(fb_invocation_c *symbol) {
TRACE("fb_invocation_c");
if (symbol->param_assignment_list != NULL)
return symbol->param_assignment_list->accept(*this);
else
return NULL;
}
/* helper symbol for fb_invocation */
/* param_assignment_list ',' param_assignment */
// SYM_LIST(param_assignment_list_c)
void *visit(param_assignment_list_c *symbol) {
TRACE("param_assignment_list_c");
return search_list(symbol);
}
/* variable_name ASSIGN expression */
// SYM_REF2(input_variable_param_assignment_c, variable_name, expression)
void *visit(input_variable_param_assignment_c *symbol) {
TRACE("input_variable_param_assignment_c");
return handle_parameter_assignment(symbol->variable_name, symbol->expression);
}
/* [NOT] variable_name '=>' variable */
// SYM_REF4(output_variable_param_assignment_c, not_param, variable_name, variable, unused)
void *visit(output_variable_param_assignment_c *symbol) {
TRACE("output_variable_param_assignment_c");
// TODO : Handle not_param !!!
if (NULL != symbol->not_param) ERROR; // we do not yet support it, so it is best to simply stop than to fail silently...
return handle_parameter_assignment(symbol->variable_name, symbol->variable);
}
/* helper CLASS for output_variable_param_assignment */
// SYM_REF0(not_paramassign_c)
// TODO... ???
};