/*
* (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)
*
*/
/*
* Conversion of st statements (i.e. ST code).
*
* This is part of the 4th stage that generates
* a c++ source program equivalent to the IL and ST
* code.
*/
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
/***********************************************************************/
class generate_cc_st_c: public generate_cc_typedecl_c {
private:
/* When calling a function block, we must first find it's type,
* by searching through the declarations of the variables currently
* in scope.
* This class does just that...
* A new class is instantiated whenever we begin generating the code
* for a function block type declaration, or a program declaration.
* This object instance will then later be called while the
* function block's or the program's body is being handled.
*
* Note that functions cannot contain calls to function blocks,
* so we do not create an object instance when handling
* a function declaration.
*/
search_fb_instance_decl_c *search_fb_instance_decl;
/* When compiling st code, it becomes necessary to determine the
* data type of st expressions. To do this, we must first find the
* st operand's declaration, within the scope of the function block
* or function currently being processed.
* The following object does just that...
* This object instance will then later be called while the
* remaining st code is being handled.
*/
search_expression_type_c *search_expression_type;
public:
generate_cc_st_c(stage4out_c *s4o_ptr, symbol_c *scope, const char *variable_prefix = NULL)
: generate_cc_typedecl_c(s4o_ptr) {
search_fb_instance_decl = new search_fb_instance_decl_c(scope);
search_expression_type = new search_expression_type_c(scope);
this->set_variable_prefix(variable_prefix);
}
virtual ~generate_cc_st_c(void) {
delete search_fb_instance_decl;
delete search_expression_type;
}
private:
/* Some function calls in the body of functions or function blocks
* may leave some parameters to their default values, and
* ignore some output parameters of the function being called.
* Our conversion of ST functions to C++ does not contemplate that,
* i.e. each called function must get all it's input and output
* parameters set correctly.
* For input parameters we merely need to call the function with
* the apropriate default value, but for output parameters
* we must create temporary variables to hold the output value.
*
* We declare all the temporary output variables at the begining of
* the body of each function or function block, and use them as
* in function calls later on as they become necessary...
* Note that we cannot create these variables just before a function
* call, as the function call itself may be integrated within an
* expression, or another function call!
*
* The variables are declared in the exact same order in which they
* will be used later on during the function calls, which allows us
* to simply re-create the name that was used for the temporary variable
* instead of keeping it in some list.
* The names are recreated by the temp_var_name_factory, after reset()
* has been called!
*
* This function will genertae code similar to...
*
* INT __TMP_0 = 23;
* REAL __TMP_1 = 45.5;
* ...
*/
temp_var_name_c temp_var_name_factory;
public:
void generate(statement_list_c *stl) {
generate_cc_tempvardecl_c generate_cc_tempvardecl(&s4o);
generate_cc_tempvardecl.generate(stl, &temp_var_name_factory);
stl->accept(*this);
}
private:
/***************************************/
/* B.3 - Language ST (Structured Text) */
/***************************************/
/***********************/
/* B 3.1 - Expressions */
/***********************/
void *visit(or_expression_c *symbol) {
symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);
symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);
if (typeid(*left_type) == typeid(bool_type_name_c) && typeid(*right_type) == typeid(bool_type_name_c)) {
return print_binary_expression(symbol->l_exp, symbol->r_exp, " || ");
}
if (search_expression_type->is_numeric_compatible(left_type) && search_expression_type->is_numeric_compatible(right_type)) {
return print_binary_expression(symbol->l_exp, symbol->r_exp, " | ");
}
ERROR;
return NULL;
}
void *visit(xor_expression_c *symbol) {
symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);
symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);
if (typeid(*left_type) == typeid(bool_type_name_c) && typeid(*right_type) == typeid(bool_type_name_c)) {
s4o.print("(");
symbol->l_exp->accept(*this);
s4o.print(" && !");
symbol->r_exp->accept(*this);
s4o.print(") || (!");
symbol->l_exp->accept(*this);
s4o.print(" && ");
symbol->r_exp->accept(*this);
s4o.print(")");
}
if (search_expression_type->is_numeric_compatible(left_type) && search_expression_type->is_numeric_compatible(right_type)) {
return print_binary_expression(symbol->l_exp, symbol->r_exp, " ^ ");
}
ERROR;
return NULL;
}
void *visit(and_expression_c *symbol) {
symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);
symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);
if (typeid(*left_type) == typeid(bool_type_name_c) && typeid(*right_type) == typeid(bool_type_name_c)) {
return print_binary_expression(symbol->l_exp, symbol->r_exp, " && ");
}
if (search_expression_type->is_numeric_compatible(left_type) && search_expression_type->is_numeric_compatible(right_type)) {
return print_binary_expression(symbol->l_exp, symbol->r_exp, " & ");
}
ERROR;
return NULL;
}
void *visit(equ_expression_c *symbol) {
symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);
symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);
if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {
return print_compare_function("__compare_timespec", "==", symbol->l_exp, symbol->r_exp);
}
return print_binary_expression(symbol->l_exp, symbol->r_exp, " == ");
}
void *visit(notequ_expression_c *symbol) {
symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);
symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);
if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {
return print_compare_function("__compare_timespec", "!=", symbol->l_exp, symbol->r_exp);
}
return print_binary_expression(symbol->l_exp, symbol->r_exp, " != ");
}
void *visit(lt_expression_c *symbol) {
symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);
symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);
if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {
return print_compare_function("__compare_timespec", "<", symbol->l_exp, symbol->r_exp);
}
return print_binary_expression(symbol->l_exp, symbol->r_exp, " < ");
}
void *visit(gt_expression_c *symbol) {
symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);
symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);
if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {
return print_compare_function("__compare_timespec", ">", symbol->l_exp, symbol->r_exp);
}
return print_binary_expression(symbol->l_exp, symbol->r_exp, " > ");
}
void *visit(le_expression_c *symbol) {
symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);
symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);
if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {
return print_compare_function("__compare_timespec", "<=", symbol->l_exp, symbol->r_exp);
}
return print_binary_expression(symbol->l_exp, symbol->r_exp, " <= ");
}
void *visit(ge_expression_c *symbol) {
symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);
symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);
if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {
return print_compare_function("__compare_timespec", ">=", symbol->l_exp, symbol->r_exp);
}
return print_binary_expression(symbol->l_exp, symbol->r_exp, " >= ");
}
void *visit(add_expression_c *symbol) {
symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);
symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);
if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {
return print_binary_function("__add_timespec", symbol->l_exp, symbol->r_exp);
}
return print_binary_expression(symbol->l_exp, symbol->r_exp, " + ");
}
void *visit(sub_expression_c *symbol) {
symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);
symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);
if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {
return print_binary_function("__sub_timespec", symbol->l_exp, symbol->r_exp);
}
return print_binary_expression(symbol->l_exp, symbol->r_exp, " - ");
}
void *visit(mul_expression_c *symbol) {
symbol_c *left_type = search_expression_type->get_type(symbol->l_exp);
symbol_c *right_type = search_expression_type->get_type(symbol->r_exp);
if (search_expression_type->is_time_compatible(left_type) && search_expression_type->is_time_compatible(right_type)) {
return print_binary_function("__mul_timespec", symbol->l_exp, symbol->r_exp);
}
return print_binary_expression(symbol->l_exp, symbol->r_exp, " * ");
}
void *visit(div_expression_c *symbol) {return print_binary_expression(symbol->l_exp, symbol->r_exp, " / ");}
void *visit(mod_expression_c *symbol) {
s4o.print("((");
symbol->r_exp->accept(*this);
s4o.print(" == 0)?0:");
print_binary_expression(symbol->l_exp, symbol->r_exp, " % ");
s4o.print(")");
return NULL;
}
/* TODO: power expression... */
void *visit(power_expression_c *symbol) {ERROR; return print_binary_expression(symbol->l_exp, symbol->r_exp, " ** ");}
void *visit(neg_expression_c *symbol) {return print_unary_expression(symbol->exp, " -");}
void *visit(not_expression_c *symbol) {return print_unary_expression(symbol->exp, "!");}
void *visit(function_invocation_c *symbol) {
function_declaration_c *f_decl = function_symtable.find_value(symbol->function_name);
if (f_decl == function_symtable.end_value())
/* should never occur. The function being called MUST be in the symtable... */
ERROR;
symbol->function_name->accept(*this);
s4o.print("(");
/* loop through each function parameter, find the value we should pass
* to it, and then output the c equivalent...
*/
function_param_iterator_c fp_iterator(f_decl);
identifier_c *param_name;
function_call_param_iterator_c function_call_param_iterator(symbol);
for(int i = 1; (param_name = fp_iterator.next()) != NULL; i++) {
if (i != 1)
s4o.print(", ");
symbol_c *param_type = fp_iterator.param_type();
if (param_type == NULL) ERROR;
function_param_iterator_c::param_direction_t param_direction = fp_iterator.param_direction();
/* Get the value from a foo(<param_name> = <param_value>) style call */
symbol_c *param_value = function_call_param_iterator.search(param_name);
/* Get the value from a foo(<param_value>) style call */
if (param_value == NULL)
param_value = function_call_param_iterator.next();
switch (param_direction) {
case function_param_iterator_c::direction_in:
if (param_value == NULL) {
/* No value given for parameter, so we must use the default... */
/* First check whether default value specified in function declaration...*/
param_value = fp_iterator.default_value();
}
if (param_value == NULL) {
/* If not, get the default value of this variable's type */
param_value = (symbol_c *)param_type->accept(*type_initial_value_c::instance());
}
if (param_value == NULL) ERROR;
param_value->accept(*this);
break;
case function_param_iterator_c::direction_out:
case function_param_iterator_c::direction_inout:
if (param_value == NULL) {
/* no parameter value given, so we pass a previously declared temporary variable. */
std::string *temp_var_name = temp_var_name_factory.new_name();
s4o.print(*temp_var_name);
delete temp_var_name;
} else {
param_value->accept(*this);
}
break;
case function_param_iterator_c::direction_extref:
/* TODO! */
ERROR;
break;
} /* switch */
} /* for(...) */
// symbol->parameter_assignment->accept(*this);
s4o.print(")");
return NULL;
}
/********************/
/* B 3.2 Statements */
/********************/
void *visit(statement_list_c *symbol) {
return print_list(symbol, s4o.indent_spaces, ";\n" + s4o.indent_spaces, ";\n");
}
/*********************************/
/* B 3.2.1 Assignment Statements */
/*********************************/
void *visit(assignment_statement_c *symbol) {
symbol->l_exp->accept(*this);
s4o.print(" = ");
symbol->r_exp->accept(*this);
return NULL;
}
/*****************************************/
/* B 3.2.2 Subprogram Control Statements */
/*****************************************/
/* 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");
/* first figure out what is the name of the function block type of the function block being called... */
symbol_c *function_block_type_name = this->search_fb_instance_decl->get_type_name(symbol->fb_name);
/* should never occur. The function block instance MUST have been declared... */
if (function_block_type_name == NULL) ERROR;
/* Now find the declaration of the function block type being called... */
function_block_declaration_c *fb_decl = function_block_type_symtable.find_value(function_block_type_name);
/* should never occur. The function block type being called MUST be in the symtable... */
if (fb_decl == function_block_type_symtable.end_value()) ERROR;
/* loop through each function block parameter, find the value we should pass
* to it, and then output the c equivalent...
*/
function_param_iterator_c fp_iterator(fb_decl);
identifier_c *param_name;
function_call_param_iterator_c function_call_param_iterator(symbol);
for(int i = 1; (param_name = fp_iterator.next()) != NULL; i++) {
function_param_iterator_c::param_direction_t param_direction = fp_iterator.param_direction();
/* Get the value from a foo(<param_name> = <param_value>) style call */
symbol_c *param_value = function_call_param_iterator.search(param_name);
/* Get the value from a foo(<param_value>) style call */
if (param_value == NULL)
param_value = function_call_param_iterator.next();
/* now output the value assignment */
if (param_value != NULL)
if ((param_direction == function_param_iterator_c::direction_in) ||
(param_direction == function_param_iterator_c::direction_inout)) {
symbol->fb_name->accept(*this);
s4o.print(".");
param_name->accept(*this);
s4o.print(" = ");
param_value->accept(*this);
s4o.print(";\n" + s4o.indent_spaces);
}
} /* for(...) */
/* now call the function... */
function_block_type_name->accept(*this);
s4o.print(FB_FUNCTION_SUFFIX);
s4o.print("(&");
symbol->fb_name->accept(*this);
s4o.print(")");
/* loop through each function parameter, find the variable to which
* we should atribute the value of all output or inoutput parameters.
*/
fp_iterator.reset();
function_call_param_iterator.reset();
for(int i = 1; (param_name = fp_iterator.next()) != NULL; i++) {
function_param_iterator_c::param_direction_t param_direction = fp_iterator.param_direction();
/* Get the value from a foo(<param_name> = <param_value>) style call */
symbol_c *param_value = function_call_param_iterator.search(param_name);
/* Get the value from a foo(<param_value>) style call */
if (param_value == NULL)
param_value = function_call_param_iterator.next();
/* now output the value assignment */
if (param_value != NULL)
if ((param_direction == function_param_iterator_c::direction_out) ||
(param_direction == function_param_iterator_c::direction_inout)) {
s4o.print(";\n"+ s4o.indent_spaces);
param_value->accept(*this);
s4o.print(" = ");
symbol->fb_name->accept(*this);
s4o.print(".");
param_name->accept(*this);
}
} /* for(...) */
return NULL;
}
/* helper symbol for fb_invocation */
/* param_assignment_list ',' param_assignment */
void *visit(param_assignment_list_c *symbol) {
TRACE("param_assignment_list_c");
/* this should never be called... */
ERROR;
return NULL;
// return print_list(symbol, "", ", ");
}
void *visit(input_variable_param_assignment_c *symbol) {
TRACE("input_variable_param_assignment_c");
/* this should never be called... */
ERROR;
return NULL;
/*
symbol->variable_name->accept(*this);
s4o.print(" = ");
symbol->expression->accept(*this);
return NULL;
*/
}
void *visit(output_variable_param_assignment_c *symbol) {
TRACE("output_variable_param_assignment_c");
/* this should never be called... */
ERROR;
return NULL;
/*
s4o.print(s4o.indent_spaces);
if (symbol->not_param != NULL)
symbol->not_param->accept(*this);
symbol->variable_name->accept(*this);
s4o.print(" => ");
symbol->variable->accept(*this);
return NULL;
*/
}
// TODO: the NOT symbol in function (block) calls...
void *visit(not_paramassign_c *symbol) {
TRACE("not_paramassign_c");
/* this should never be called... */
ERROR;
return NULL;
/*
s4o.print("NOT ");
return NULL;
*/
}
/********************************/
/* B 3.2.3 Selection Statements */
/********************************/
void *visit(if_statement_c *symbol) {
s4o.print("if (");
symbol->expression->accept(*this);
s4o.print(") {\n");
s4o.indent_right();
symbol->statement_list->accept(*this);
s4o.indent_left();
symbol->elseif_statement_list->accept(*this);
if (symbol->else_statement_list != NULL) {
s4o.print(s4o.indent_spaces); s4o.print("} else {\n");
s4o.indent_right();
symbol->else_statement_list->accept(*this);
s4o.indent_left();
}
s4o.print(s4o.indent_spaces); s4o.print("}");
return NULL;
}
/* helper symbol for if_statement */
void *visit(elseif_statement_list_c *symbol) {return print_list(symbol);}
/* helper symbol for elseif_statement_list */
void *visit(elseif_statement_c *symbol) {
s4o.print(s4o.indent_spaces); s4o.print("} else if (");
symbol->expression->accept(*this);
s4o.print(") {\n");
s4o.indent_right();
symbol->statement_list->accept(*this);
s4o.indent_left();
return NULL;
}
void *visit(case_statement_c *symbol) {
s4o.print("switch(");
symbol->expression->accept(*this);
s4o.print(") {\n");
s4o.indent_right();
symbol->case_element_list->accept(*this);
if (symbol->statement_list != NULL) {
s4o.print(s4o.indent_spaces + "default:\n");
s4o.indent_right();
symbol->statement_list->accept(*this);
s4o.print(s4o.indent_spaces + "break;\n");
s4o.indent_left();
}
s4o.indent_left();
s4o.print(s4o.indent_spaces + "}");
return NULL;
}
/* helper symbol for case_statement */
void *visit(case_element_list_c *symbol) {return print_list(symbol);}
void *visit(case_element_c *symbol) {
s4o.print(s4o.indent_spaces + "case ");
symbol->case_list->accept(*this);
s4o.print(" :\n");
s4o.indent_right();
symbol->statement_list->accept(*this);
s4o.print(s4o.indent_spaces + "break;\n");
s4o.indent_left();
return NULL;
}
void *visit(case_list_c *symbol) {return print_list(symbol, "", ", ");}
/********************************/
/* B 3.2.4 Iteration Statements */
/********************************/
void *visit(for_statement_c *symbol) {
s4o.print("for(");
symbol->control_variable->accept(*this);
s4o.print(" = ");
symbol->beg_expression->accept(*this);
s4o.print("; ");
symbol->control_variable->accept(*this);
s4o.print(" != ");
symbol->end_expression->accept(*this);
s4o.print("; ");
symbol->control_variable->accept(*this);
if (symbol->by_expression != NULL) {
s4o.print(" += ");
symbol->by_expression->accept(*this);
} else {
s4o.print("++");
}
s4o.print(") {\n");
s4o.indent_right();
symbol->statement_list->accept(*this);
s4o.indent_left();
s4o.print(s4o.indent_spaces); s4o.print("}");
return NULL;
}
void *visit(while_statement_c *symbol) {
s4o.print("while (");
symbol->expression->accept(*this);
s4o.print(") {\n");
s4o.indent_right();
symbol->statement_list->accept(*this);
s4o.indent_left();
s4o.print(s4o.indent_spaces); s4o.print("}");
return NULL;
}
void *visit(repeat_statement_c *symbol) {
s4o.print("do {\n");
s4o.indent_right();
symbol->statement_list->accept(*this);
s4o.indent_left();
s4o.print(s4o.indent_spaces); s4o.print("} while(");
symbol->expression->accept(*this);
s4o.print(")");
return NULL;
}
void *visit(exit_statement_c *symbol) {
s4o.print("exit(0)");
return NULL;
}
}; /* generate_cc_st_c */