--- /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(<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 */
+
+
+
+
+
+
+
+
+