diff -r 000000000000 -r fb772792efd1 stage4/generate_cc/generate_cc_st.cc --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/stage4/generate_cc/generate_cc_st.cc Wed Jan 31 15:32:38 2007 +0100 @@ -0,0 +1,506 @@ +/* + * (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; + + + 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); + this->set_variable_prefix(variable_prefix); + } + + virtual ~generate_cc_st_c(void) { + delete search_fb_instance_decl; + } + + + 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) {return print_binary_expression(symbol->l_exp, symbol->r_exp, " || ");} +/* TODO ... XOR expression... */ +void *visit(xor_expression_c *symbol) {ERROR; return print_binary_expression(symbol->l_exp, symbol->r_exp, " XOR ");} +void *visit(and_expression_c *symbol) {return print_binary_expression(symbol->l_exp, symbol->r_exp, " && ");} +void *visit(equ_expression_c *symbol) {return print_binary_expression(symbol->l_exp, symbol->r_exp, " == ");} +void *visit(notequ_expression_c *symbol) {return print_binary_expression(symbol->l_exp, symbol->r_exp, " != ");} +void *visit(lt_expression_c *symbol) {return print_binary_expression(symbol->l_exp, symbol->r_exp, " < ");} +void *visit(gt_expression_c *symbol) {return print_binary_expression(symbol->l_exp, symbol->r_exp, " > ");} +void *visit(le_expression_c *symbol) {return print_binary_expression(symbol->l_exp, symbol->r_exp, " <= ");} +void *visit(ge_expression_c *symbol) {return print_binary_expression(symbol->l_exp, symbol->r_exp, " >= ");} +void *visit(add_expression_c *symbol) {return print_binary_expression(symbol->l_exp, symbol->r_exp, " + ");} +void *visit(sub_expression_c *symbol) {return print_binary_expression(symbol->l_exp, symbol->r_exp, " - ");} +void *visit(mul_expression_c *symbol) {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( = ) style call */ + symbol_c *param_value = function_call_param_iterator.search(param_name); + + /* Get the value from a foo() 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( = ) style call */ + symbol_c *param_value = function_call_param_iterator.search(param_name); + + /* Get the value from a foo() 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( = ) style call */ + symbol_c *param_value = function_call_param_iterator.search(param_name); + + /* Get the value from a foo() 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 */ + + + + + + + + +