--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/stage4/generate_cc/generate_cc_il.cc Wed Jan 31 15:32:38 2007 +0100
@@ -0,0 +1,1283 @@
+/*
+ * (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 il statements (i.e. IL code).
+ *
+ * This is part of the 4th stage that generates
+ * a c++ source program equivalent to the IL and ST
+ * code.
+ */
+
+
+
+
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+
+/* Returns the data type of an il_operand.
+ *
+ * Note that the il_operand may be a variable, in which case
+ * we return the type of the variable instance.
+ * The il_operand may also be a constant, in which case
+ * we return the data type of that constant.
+ *
+ * The variable instance may be a member of a structured variable,
+ * or an element in an array, or any combination of the two.
+ *
+ * The class constructor must be given the search scope
+ * (function, function block or program within which
+ * the possible il_operand variable instance was declared).
+ */
+class search_il_operand_type_c {
+
+ private:
+ search_varfb_instance_type_c search_varfb_instance_type;
+ search_constant_type_c search_constant_type;
+
+ public:
+ search_il_operand_type_c(symbol_c *search_scope): search_varfb_instance_type(search_scope) {}
+
+ public:
+ symbol_c *get_type(symbol_c *il_operand) {
+ symbol_c *res;
+
+ /* We first assume that it is a constant... */
+ res = search_constant_type.get_type(il_operand);
+ if (res != NULL) return res;
+
+ /* Nope, now we assume it is a variable, and determine its type... */
+ res = search_varfb_instance_type.get_type(il_operand);
+ if (NULL != res) return res;
+
+ /* not found */
+ return NULL;
+ }
+};
+
+
+
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+
+
+/* A new class to ouput the il default variable to c++ code
+ * We use this class, inheriting from symbol_c, so it may be used
+ * as any other symbol_c object in the intermediate parse tree,
+ * more specifically, so it can be used as any other il operand.
+ * This makes the rest of the code much easier...
+ *
+ * Nevertheless, the basic visitor class visitor_c does not know
+ * how to visit this new il_default_variable_c class, so we have
+ * to extend that too.
+ * In reality extending the basic symbols doesn't quite work out
+ * as cleanly as desired (we need to use dynamic_cast in the
+ * accept method of the il_default_variable_c), but it is cleaner
+ * than the alternative...
+ */
+class il_default_variable_c;
+
+/* This visitor class is not really required, we could place the
+ * visit() method directly in genertae_cc_il_c, but doing it in
+ * a seperate class makes the architecture more evident...
+ */
+class il_default_variable_visitor_c {
+ public:
+ virtual void *visit(il_default_variable_c *symbol) = 0;
+
+ virtual ~il_default_variable_visitor_c(void) {return;}
+};
+
+
+/* A class to print out to the resulting C++ code
+ * the IL default variable name.
+ *
+ * It includes a reference to its name,
+ * and the data type of the data currently stored
+ * in this C++ variable... This is required because the
+ * C++ variable is a union, and we must know which member
+ * of the union top reference!!
+ *
+ * Note that we also need to keep track of the data type of
+ * the value currently being stored in the default variable.
+ * This is required so we can process parenthesis,
+ *
+ * e.g. :
+ * LD var1
+ * AND (
+ * LD var2
+ * OR var3
+ * )
+ *
+ * Note that we only execute the 'AND (' operation when we come across
+ * the ')', i.e. once we have evaluated the result of the
+ * instructions inside the parenthesis.
+ * When we do execute the 'AND (' operation, we need to know the data type
+ * of the operand, which in this case is the result of the evaluation of the
+ * instruction list inside the parenthesis. We can only know this if we
+ * keep track of the data type currently stored in the default variable!
+ *
+ * We use the current_type inside the generate_cc_il::default_variable_name variable
+ * to track this!
+ */
+class il_default_variable_c: public symbol_c {
+ public:
+ symbol_c *var_name; /* in principle, this should point to an indentifier_c */
+ symbol_c *current_type;
+
+ public:
+ il_default_variable_c(const char *var_name_str, symbol_c *current_type);
+ virtual void *accept(visitor_c &visitor);
+};
+
+
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+
+
+
+class generate_cc_il_c: public generate_cc_typedecl_c, il_default_variable_visitor_c {
+
+ private:
+ /* When compiling il code, it becomes necessary to determine the
+ * data type of il operands. To do this, we must first find the
+ * il 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 il code is being handled.
+ */
+ search_il_operand_type_c *search_il_operand_type;
+
+ /* The initial value that should be given to the IL default variable
+ * imediately after a parenthesis is opened.
+ * This variable is only used to pass data from the
+ * il_expression_c visitor to the simple_instr_list_c visitor.
+ *
+ * e.g.:
+ * LD var1
+ * AND ( var2
+ * OR var3
+ * )
+ *
+ * In the above code sample, the line 'AND ( var2' constitutes
+ * an il_expression_c, where var2 should be loaded into the
+ * il default variable before continuing with the expression
+ * inside the parenthesis.
+ * Unfortunately, only the simple_instr_list_c may do the
+ * initial laoding of the var2 bariable following the parenthesis,
+ * so the il_expression_c visitor will have to pass 'var2' as a
+ * parameter to the simple_instr_list_c visitor.
+ * Ergo, the existance of the following parameter...!
+ */
+ symbol_c *il_default_variable_init_value;
+
+ /* Operand to the IL operation currently being processed... */
+ /* These variables are used to pass data from the
+ * il_simple_operation_c and il_expression_c visitors
+ * to the il operator visitors (i.e. LD_operator_c,
+ * LDN_operator_c, ST_operator_c, STN_operator_c, ...)
+ */
+ symbol_c *current_operand;
+ symbol_c *current_operand_type;
+
+ /* Label to which the current IL jump operation should jump to... */
+ /* This variable is used to pass data from the
+ * il_jump_operation_c visitor
+ * to the il jump operator visitors (i.e. JMP_operator_c,
+ * JMPC_operator_c, JMPCN_operator_c, ...)
+ */
+ symbol_c *jump_label;
+
+ /* The result of the comparison IL operations (GT, EQ, LT, ...)
+ * is a boolean variable.
+ * This class keeps track of the current data type stored in the
+ * il default variable. This is usually done by keeping a reference
+ * to the data type of the last operand. Nevertheless, in the case of
+ * the comparison IL operators, the data type of the result (a boolean)
+ * is not the data type of the operand. We therefore need an object
+ * of the boolean data type to keep as a reference of the current
+ * data type.
+ * The following object is it...
+ */
+ bool_type_name_c bool_type;
+
+ /* the data type of the IL default variable... */
+ #define IL_DEFVAR_T VAR_LEADER "IL_DEFVAR_T"
+ /* The name of the IL default variable... */
+ #define IL_DEFVAR VAR_LEADER "IL_DEFVAR"
+ /* The name of the variable used to pass the result of a
+ * parenthesised instruction list to the immediately preceding
+ * scope ...
+ */
+ #define IL_DEFVAR_BACK VAR_LEADER "IL_DEFVAR_BACK"
+ il_default_variable_c default_variable_name;
+ il_default_variable_c default_variable_back_name;
+
+ /* 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;
+
+ /* 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_il_c(stage4out_c *s4o_ptr, symbol_c *scope, const char *variable_prefix = NULL)
+ : generate_cc_typedecl_c(s4o_ptr),
+ default_variable_name(IL_DEFVAR, NULL),
+ default_variable_back_name(IL_DEFVAR_BACK, NULL)
+ {
+ search_il_operand_type = new search_il_operand_type_c(scope);
+ search_fb_instance_decl = new search_fb_instance_decl_c(scope);
+ current_operand = NULL;
+ current_operand_type = NULL;
+ il_default_variable_init_value = NULL;
+ this->set_variable_prefix(variable_prefix);
+ }
+
+ virtual ~generate_cc_il_c(void) {
+ delete search_fb_instance_decl;
+ delete search_il_operand_type;
+ }
+
+ void generate(instruction_list_c *il) {
+ generate_cc_tempvardecl_c generate_cc_tempvardecl(&s4o);
+ generate_cc_tempvardecl.generate(il, &temp_var_name_factory);
+ il->accept(*this);
+ }
+
+ private:
+ /* A helper function... */
+ bool is_bool_type(symbol_c *type_symbol) {
+ return (NULL != dynamic_cast<bool_type_name_c *>(type_symbol));
+ }
+
+ /* A helper function... */
+ void *XXX_operator(symbol_c *lo, const char *op, symbol_c *ro) {
+ if ((NULL == lo) || (NULL == ro)) ERROR;
+ if (NULL == op) ERROR;
+
+ lo->accept(*this);
+ s4o.print(op);
+ ro->accept(*this);
+ return NULL;
+ }
+
+ /* A helper function... */
+ void *XXX_CAL_operator(const char *param_name, symbol_c *fb_name) {
+ if (NULL == fb_name) ERROR;
+ symbolic_variable_c *sv = dynamic_cast<symbolic_variable_c *>(fb_name);
+ if (NULL == sv) ERROR;
+ identifier_c *id = dynamic_cast<identifier_c *>(sv->var_name);
+ if (NULL == id) ERROR;
+
+ identifier_c param(param_name);
+
+ //SYM_REF4(il_param_assignment_c, il_assign_operator, il_operand, simple_instr_list, unused)
+ il_param_assignment_c il_param_assignment(¶m, &this->default_variable_name, NULL, NULL);
+ // SYM_LIST(il_param_list_c)
+ il_param_list_c il_param_list;
+ il_param_list.add_element(&il_param_assignment);
+ CAL_operator_c CAL_operator;
+ // SYM_REF4(il_fb_call_c, il_call_operator, fb_name, il_operand_list, il_param_list)
+ il_fb_call_c il_fb_call(&CAL_operator, id, NULL, &il_param_list);
+
+ il_fb_call.accept(*this);
+ return NULL;
+ }
+
+ /* A helper function... */
+ void *CMP_operator(symbol_c *o, const char *operation) {
+ if (NULL == o) ERROR;
+ if (NULL == this->default_variable_name.current_type) ERROR;
+
+ symbol_c *backup = this->default_variable_name.current_type;
+ this->default_variable_name.current_type = &(this->bool_type);
+ this->default_variable_name.accept(*this);
+ this->default_variable_name.current_type = backup;
+
+ s4o.print(" = (");
+ this->default_variable_name.accept(*this);
+ s4o.print(operation);
+ o->accept(*this);
+ s4o.print(")");
+
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = &(this->bool_type);
+ return NULL;
+ }
+
+
+ /* A helper function... */
+ void C_modifier(void) {
+ if (NULL == this->default_variable_name.current_type) ERROR;
+
+ s4o.print("if (");
+ this->default_variable_name.accept(*this);
+ s4o.print(") ");
+ }
+
+ /* A helper function... */
+ void CN_modifier(void) {
+ if (NULL == this->default_variable_name.current_type) ERROR;
+
+ s4o.print("if (!");
+ this->default_variable_name.accept(*this);
+ s4o.print(") ");
+ }
+
+
+public:
+void *visit(il_default_variable_c *symbol) {
+ //s4o.print("il_default_variable_c VISITOR!!\n");
+ symbol->var_name->accept(*this);
+ if (NULL != symbol->current_type) {
+ s4o.print(".");
+ symbol->current_type->accept(*this);
+ s4o.print("var");
+ }
+ return NULL;
+}
+
+
+private:
+/****************************************/
+/* B.2 - Language IL (Instruction List) */
+/****************************************/
+
+/***********************************/
+/* B 2.1 Instructions and Operands */
+/***********************************/
+
+/* please see the comment before the RET_operator_c visitor for details... */
+#define END_LABEL VAR_LEADER "end"
+
+/*| instruction_list il_instruction */
+void *visit(instruction_list_c *symbol) {
+ /* Declare the backup to the default variable, that will store the result
+ * of the IL operations executed inside a parenthesis...
+ */
+ s4o.print(s4o.indent_spaces);
+ s4o.print(IL_DEFVAR_T);
+ s4o.print(" ");
+ this->default_variable_back_name.accept(*this);
+ s4o.print(";\n");
+
+ /* Declare the default variable, that will store the result of the IL operations... */
+ s4o.print(s4o.indent_spaces);
+ s4o.print(IL_DEFVAR_T);
+ s4o.print(" ");
+ this->default_variable_name.accept(*this);
+ s4o.print(";\n\n");
+
+ print_list(symbol, s4o.indent_spaces, ";\n" + s4o.indent_spaces, ";\n");
+
+ /* write the label marking the end of the code block */
+ /* please see the comment before the RET_operator_c visitor for details... */
+ s4o.print("\n");
+ s4o.print(s4o.indent_spaces);
+ s4o.print(END_LABEL);
+ s4o.print(":\n");
+ s4o.indent_right();
+ /* since every label must be followed by at least one statement, and
+ * only the functions will introduce the return statement after this label,
+ * function blocks written in IL would result in invalid C++ code.
+ * To work around this we introduce the equivalent of a 'nop' operation
+ * to humour the compiler...
+ */
+ s4o.print(s4o.indent_spaces);
+ s4o.print("/* to humour the compiler, we insert a nop */\n");
+ s4o.print(s4o.indent_spaces);
+ this->default_variable_name.accept(*this);
+ s4o.print(" = ");
+ this->default_variable_name.accept(*this);
+ s4o.print(";\n");
+ s4o.indent_left();
+
+ return NULL;
+}
+
+
+/* | label ':' [il_incomplete_instruction] eol_list */
+// SYM_REF2(il_instruction_c, label, il_instruction)
+void *visit(il_instruction_c *symbol) {
+ if (NULL != symbol->label) {
+ symbol->label->accept(*this);
+ s4o.print(":\n");
+ s4o.print(s4o.indent_spaces);
+ }
+ symbol->il_instruction->accept(*this);
+ return NULL;
+}
+
+/* | il_simple_operator [il_operand] */
+//SYM_REF2(il_simple_operation_c, il_simple_operator, il_operand)
+void *visit(il_simple_operation_c *symbol) {
+ this->current_operand = symbol->il_operand;
+ if (NULL == this->current_operand) {
+ this->current_operand_type = NULL;
+ } else {
+ this->current_operand_type = search_il_operand_type->get_type(this->current_operand);
+ if (NULL == this->current_operand_type) ERROR;
+ }
+
+ symbol->il_simple_operator->accept(*this);
+
+ this->current_operand = NULL;
+ this->current_operand_type = NULL;
+ return NULL;
+}
+
+
+/* | function_name [il_operand_list] */
+// SYM_REF2(il_function_call_c, function_name, il_operand_list)
+void *visit(il_function_call_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;
+
+ /* determine the base data type returned by the function being called... */
+ search_base_type_c search_base_type;
+ symbol_c *return_data_type = (symbol_c *)f_decl->type_name->accept(search_base_type);
+ symbol_c *param_data_type = default_variable_name.current_type;
+ if (NULL == return_data_type) ERROR;
+
+ default_variable_name.current_type = return_data_type;
+ this->default_variable_name.accept(*this);
+ default_variable_name.current_type = param_data_type;
+ s4o.print(" = ");
+
+ 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();
+
+
+ symbol_c *param_value = NULL;
+
+ /* if it is the first parameter, semantics specifies that we should
+ * get the value off the IL default variable!
+ */
+ if (1 == i)
+ param_value = &this->default_variable_name;
+
+ /* Get the value from a foo(<param_name> = <param_value>) style call */
+ /* NOTE: the following line of code is not required in this case, but it doesn't
+ * harm to leave it in, as in the case of a non-formal syntax function call,
+ * it will always return NULL.
+ * We leave it in in case we later decide to merge this part of the code together
+ * with the function calling code in generate_cc_st_c, which does require
+ * the following line...
+ */
+ if (param_value == NULL)
+ 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(...) */
+
+ s4o.print(")");
+
+ /* the data type returned by the function, and stored in the il default variable... */
+ default_variable_name.current_type = return_data_type;
+
+ return NULL;
+}
+
+
+/* | il_expr_operator '(' [il_operand] eol_list [simple_instr_list] ')' */
+//SYM_REF4(il_expression_c, il_expr_operator, il_operand, simple_instr_list, unused)
+void *visit(il_expression_c *symbol) {
+ /* We will be recursevely interpreting an instruction list,
+ * so we store a backup of the data type of the value currently stored
+ * in the default variable, and set the current data type to NULL
+ */
+ symbol_c *old_current_default_variable_data_type = this->default_variable_name.current_type;
+ this->default_variable_name.current_type = NULL;
+
+ /* Pass the symbol->il_operand to the simple_instr_list visitor
+ * using the il_default_variable_init_value parameter...
+ * Note that the simple_instr_list_c visitor will set this parameter
+ * to NULL as soon as it does not require it any longer,
+ * so we don't do it here again after the
+ * symbol->simple_instr_list->accept(*this);
+ * returns...
+ */
+ this->il_default_variable_init_value = symbol->il_operand;
+
+ /* Now do the parenthesised instructions... */
+ /* NOTE: the following code line will get the variable
+ * this->default_variable_name.current_type updated!
+ */
+ symbol->simple_instr_list->accept(*this);
+
+ /* Now do the operation, using the previous result! */
+ /* NOTE: The result of the previous instruction list will be stored
+ * in a variable named IL_DEFVAR_BACK. This is done in the visitor
+ * to instruction_list_c objects...
+ */
+ this->current_operand = &(this->default_variable_back_name);
+ this->current_operand_type = this->default_variable_back_name.current_type;
+
+ this->default_variable_name.current_type = old_current_default_variable_data_type;
+ if (NULL == this->current_operand_type) ERROR;
+
+ symbol->il_expr_operator->accept(*this);
+
+ this->current_operand = NULL;
+ this->current_operand_type = NULL;
+ this->default_variable_back_name.current_type = NULL;
+ return NULL;
+}
+
+/* il_jump_operator label */
+// SYM_REF2(il_jump_operation_c, il_jump_operator, label)
+void *visit(il_jump_operation_c *symbol) {
+ /* Pass the symbol->label to the il_jump_operation visitor
+ * using the jump_label parameter...
+ */
+ this->jump_label = symbol->label;
+ symbol->il_jump_operator->accept(*this);
+ this->jump_label = NULL;
+
+ 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) {
+ symbol->il_call_operator->accept(*this);
+ s4o.print("{\n");
+ s4o.indent_right();
+ s4o.print(s4o.indent_spaces);
+
+ /* 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(...) */
+
+ s4o.print(";\n");
+ s4o.indent_left();
+ s4o.print(s4o.indent_spaces);
+ s4o.print("}");
+
+ 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) {
+ 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();
+
+
+ symbol_c *param_value = NULL;
+
+ /* Get the value from a foo(<param_name> = <param_value>) style call */
+ if (param_value == NULL)
+ param_value = function_call_param_iterator.search(param_name);
+
+ /* Get the value from a foo(<param_value>) style call */
+ /* NOTE: the following line of code is not required in this case, but it doesn't
+ * harm to leave it in, as in the case of a formal syntax function call,
+ * it will always return NULL.
+ * We leave it in in case we later decide to merge this part of the code together
+ * with the function calling code in generate_cc_st_c, which does require
+ * the following line...
+ */
+ 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;
+}
+
+
+/* | il_operand_list ',' il_operand */
+// SYM_LIST(il_operand_list_c)
+void *visit(il_operand_list_c *symbol) {ERROR; return NULL;} // should never get called!
+
+
+/* | simple_instr_list il_simple_instruction */
+// SYM_LIST(simple_instr_list_c)
+void *visit(simple_instr_list_c *symbol) {
+ /* A simple_instr_list_c is used to store a list of il operations
+ * being done within parenthesis...
+ *
+ * e.g.:
+ * LD var1
+ * AND ( var2
+ * OR var3
+ * OR var4
+ * )
+ *
+ * This will be converted to C++ by defining a new scope
+ * with a new il default variable, and executing the il operands
+ * within this new scope.
+ * At the end of the scope the result, i.e. the value currently stored
+ * in the il default variable is copied to the variable used to take this
+ * value to the outside scope...
+ *
+ * The above example will result in the following C++ code:
+ * {__IL_DEFVAR_T __IL_DEFVAR_BACK;
+ * __IL_DEFVAR_T __IL_DEFVAR;
+ *
+ * __IL_DEFVAR.INTvar = var1;
+ * {
+ * __IL_DEFVAR_T __IL_DEFVAR;
+ *
+ * __IL_DEFVAR.INTvar = var2;
+ * __IL_DEFVAR.INTvar |= var3;
+ * __IL_DEFVAR.INTvar |= var4;
+ *
+ * __IL_DEFVAR_BACK = __IL_DEFVAR;
+ * }
+ * __IL_DEFVAR.INTvar &= __IL_DEFVAR_BACK.INTvar;
+ *
+ * }
+ *
+ * The intial value of the il default variable (in the above
+ * example 'var2') is passed to this simple_instr_list_c visitor
+ * using the il_default_variable_init_value parameter.
+ * Since it is possible to have parenthesis inside other parenthesis
+ * recursively, we reset the il_default_variable_init_value to NULL
+ * as soon as we no longer require it, as it may be used once again
+ * in the line
+ * print_list(symbol, s4o.indent_spaces, ";\n" + s4o.indent_spaces, ";\n");
+ *
+ */
+
+ /* Declare the default variable, that will store the result of the IL operations... */
+ s4o.print("{\n");
+ s4o.indent_right();
+
+ s4o.print(s4o.indent_spaces);
+ s4o.print(IL_DEFVAR_T);
+ s4o.print(" ");
+ this->default_variable_name.accept(*this);
+ s4o.print(";\n\n");
+
+ /* Check whether we should initiliase the il default variable... */
+ if (NULL != this->il_default_variable_init_value) {
+ /* Yes, we must... */
+ /* We will do it by instatiating a LD operator, and having this
+ * same generate_cc_il_c class visiting it!
+ */
+ LD_operator_c ld_oper;
+ il_simple_operation_c il_simple_oper(&ld_oper, this->il_default_variable_init_value);
+
+ s4o.print(s4o.indent_spaces);
+ il_simple_oper.accept(*this);
+ s4o.print(";\n");
+ }
+
+ /* this parameter no longer required... */
+ this->il_default_variable_init_value = NULL;
+
+ print_list(symbol, s4o.indent_spaces, ";\n" + s4o.indent_spaces, ";\n");
+
+ /* copy the result in the default variable to the variable
+ * used to pass the data out to the scope enclosing
+ * the current scope!
+ *
+ * We also need to update the data type currently stored within
+ * the variable used to pass the data to the outside scope...
+ */
+ this->default_variable_back_name.current_type = this->default_variable_name.current_type;
+ s4o.print("\n");
+ s4o.print(s4o.indent_spaces);
+ this->default_variable_back_name.accept(*this);
+ s4o.print(" = ");
+ this->default_variable_name.accept(*this);
+ s4o.print(";\n");
+
+ s4o.indent_left();
+ s4o.print(s4o.indent_spaces);
+ s4o.print("}\n");
+ s4o.print(s4o.indent_spaces);
+ return NULL;
+}
+
+/* | il_initial_param_list il_param_instruction */
+// SYM_LIST(il_param_list_c)
+void *visit(il_param_list_c *symbol) {ERROR; return NULL;} // should never get called!
+
+/* 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) {ERROR; return NULL;} // should never get called!
+
+/* 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) {ERROR; return NULL;} // should never get called!
+
+/*******************/
+/* B 2.2 Operators */
+/*******************/
+
+void *visit(LD_operator_c *symbol) {
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = this->current_operand_type;
+ XXX_operator(&(this->default_variable_name), " = ", this->current_operand);
+ return NULL;
+}
+
+void *visit(LDN_operator_c *symbol) {
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = this->current_operand_type;
+ XXX_operator(&(this->default_variable_name),
+ is_bool_type(this->current_operand_type)?" = !":" = ~",
+ this->current_operand);
+ return NULL;
+}
+
+void *visit(ST_operator_c *symbol) {
+ XXX_operator(this->current_operand, " = ",&(this->default_variable_name));
+ /* the data type resulting from this operation is unchamged. */
+ return NULL;
+}
+
+void *visit(STN_operator_c *symbol) {
+ XXX_operator(this->current_operand,
+ is_bool_type(this->current_operand_type)?" = !":" = ~",
+ &(this->default_variable_name));
+ /* the data type resulting from this operation is unchamged. */
+ return NULL;
+}
+
+void *visit(NOT_operator_c *symbol) {
+ if ((NULL != this->current_operand) || (NULL != this->current_operand_type)) ERROR;
+ XXX_operator(&(this->default_variable_name),
+ is_bool_type(this->default_variable_name.current_type)?" = !":" = ~",
+ &(this->default_variable_name));
+ /* the data type resulting from this operation is unchanged. */
+ return NULL;
+}
+
+void *visit(S_operator_c *symbol) {
+ if ((NULL == this->current_operand) || (NULL == this->current_operand_type)) ERROR;
+
+ C_modifier();
+ this->current_operand->accept(*this);
+ s4o.print(is_bool_type(this->current_operand_type)?" = true":" = 1");
+ /* the data type resulting from this operation is unchanged! */
+ return NULL;
+}
+
+void *visit(R_operator_c *symbol) {
+ if ((NULL == this->current_operand) || (NULL == this->current_operand_type)) ERROR;
+
+ C_modifier();
+ this->current_operand->accept(*this);
+ s4o.print(is_bool_type(this->current_operand_type)?" = false":" = 0");
+ /* the data type resulting from this operation is unchanged! */
+ return NULL;
+}
+
+void *visit(S1_operator_c *symbol) {return XXX_CAL_operator("S1", this->current_operand);}
+void *visit(R1_operator_c *symbol) {return XXX_CAL_operator("R1", this->current_operand);}
+void *visit(CLK_operator_c *symbol) {return XXX_CAL_operator("CLK", this->current_operand);}
+void *visit(CU_operator_c *symbol) {return XXX_CAL_operator("CU", this->current_operand);}
+void *visit(CD_operator_c *symbol) {return XXX_CAL_operator("CD", this->current_operand);}
+void *visit(PV_operator_c *symbol) {return XXX_CAL_operator("PV", this->current_operand);}
+void *visit(IN_operator_c *symbol) {return XXX_CAL_operator("IN", this->current_operand);}
+void *visit(PT_operator_c *symbol) {return XXX_CAL_operator("PT", this->current_operand);}
+
+void *visit(AND_operator_c *symbol) {
+ XXX_operator(&(this->default_variable_name), " &= ", this->current_operand);
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = this->current_operand_type;
+ return NULL;
+}
+
+void *visit(OR_operator_c *symbol) {
+ XXX_operator(&(this->default_variable_name), " |= ", this->current_operand);
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = this->current_operand_type;
+ return NULL;
+}
+
+void *visit(XOR_operator_c *symbol) {
+ // '^' is a bit by bit exclusive OR !! Also seems to work with boolean types!
+ XXX_operator(&(this->default_variable_name), " ^= ", this->current_operand);
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = this->current_operand_type;
+ return NULL;
+}
+
+void *visit(ANDN_operator_c *symbol) {
+ XXX_operator(&(this->default_variable_name),
+ is_bool_type(this->current_operand_type)?" &= !":" &= ~",
+ this->current_operand);
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = this->current_operand_type;
+ return NULL;
+}
+
+void *visit(ORN_operator_c *symbol) {
+ XXX_operator(&(this->default_variable_name),
+ is_bool_type(this->current_operand_type)?" |= !":" |= ~",
+ this->current_operand);
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = this->current_operand_type;
+ return NULL;
+}
+
+void *visit(XORN_operator_c *symbol) {
+ XXX_operator(&(this->default_variable_name),
+ // bit by bit exclusive OR !! Also seems to work with boolean types!
+ is_bool_type(this->current_operand_type)?" ^= !":" ^= ~",
+ this->current_operand);
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = this->current_operand_type;
+ return NULL;
+}
+
+void *visit(ADD_operator_c *symbol) {
+ XXX_operator(&(this->default_variable_name), " += ", this->current_operand);
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = this->current_operand_type;
+ return NULL;
+}
+
+void *visit(SUB_operator_c *symbol) {
+ XXX_operator(&(this->default_variable_name), " -= ", this->current_operand);
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = this->current_operand_type;
+ return NULL;
+}
+
+void *visit(MUL_operator_c *symbol) {
+ XXX_operator(&(this->default_variable_name), " *= ", this->current_operand);
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = this->current_operand_type;
+ return NULL;
+}
+
+void *visit(DIV_operator_c *symbol) {
+ XXX_operator(&(this->default_variable_name), " /= ", this->current_operand);
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = this->current_operand_type;
+ return NULL;
+}
+
+void *visit(MOD_operator_c *symbol) {
+ XXX_operator(&(this->default_variable_name), " %= ", this->current_operand);
+ /* the data type resulting from this operation... */
+ this->default_variable_name.current_type = this->current_operand_type;
+ return NULL;
+}
+
+void *visit(GT_operator_c *symbol) {
+ return CMP_operator(this->current_operand, " > ");
+}
+
+void *visit(GE_operator_c *symbol) {
+ return CMP_operator(this->current_operand, " >= ");
+}
+
+void *visit(EQ_operator_c *symbol) {
+ return CMP_operator(this->current_operand, " == ");
+}
+
+void *visit(LT_operator_c *symbol) {
+ return CMP_operator(this->current_operand, " < ");
+}
+
+void *visit(LE_operator_c *symbol) {
+ return CMP_operator(this->current_operand, " <= ");
+}
+
+void *visit(NE_operator_c *symbol) {
+ return CMP_operator(this->current_operand, " != ");
+}
+
+
+//SYM_REF0(CAL_operator_c)
+// This method will be called from within the il_fb_call_c visitor method
+void *visit(CAL_operator_c *symbol) {return NULL;}
+
+//SYM_REF0(CALC_operator_c)
+// This method will be called from within the il_fb_call_c visitor method
+void *visit(CALC_operator_c *symbol) {C_modifier(); return NULL;}
+
+//SYM_REF0(CALCN_operator_c)
+// This method will be called from within the il_fb_call_c visitor method
+void *visit(CALCN_operator_c *symbol) {CN_modifier(); return NULL;}
+
+/* NOTE: The semantics of the RET operator requires us to return a value
+ * if the IL code is inside a function, but simply return no value if
+ * the IL code is inside a function block or program!
+ * Nevertheless, it is the generate_cc_c class itself that
+ * introduces the 'reaturn <value>' into the c++ code at the end
+ * of every function. This class does not know whether the IL code
+ * is inside a function or a function block.
+ * We work around this by jumping to the end of the code,
+ * that will be marked by the END_LABEL label in the
+ * instruction_list_c visitor...
+ */
+// SYM_REF0(RET_operator_c)
+void *visit(RET_operator_c *symbol) {
+ s4o.print("goto ");s4o.print(END_LABEL);
+ return NULL;
+}
+
+// SYM_REF0(RETC_operator_c)
+void *visit(RETC_operator_c *symbol) {
+ C_modifier();
+ s4o.print("goto ");s4o.print(END_LABEL);
+ return NULL;
+}
+
+// SYM_REF0(RETCN_operator_c)
+void *visit(RETCN_operator_c *symbol) {
+ CN_modifier();
+ s4o.print("goto ");s4o.print(END_LABEL);
+ return NULL;
+}
+
+//SYM_REF0(JMP_operator_c)
+void *visit(JMP_operator_c *symbol) {
+ if (NULL == this->jump_label) ERROR;
+
+ s4o.print("goto ");
+ this->jump_label->accept(*this);
+ /* the data type resulting from this operation is unchanged! */
+ return NULL;
+}
+
+// SYM_REF0(JMPC_operator_c)
+void *visit(JMPC_operator_c *symbol) {
+ if (NULL == this->jump_label) ERROR;
+
+ C_modifier();
+ s4o.print("goto ");
+ this->jump_label->accept(*this);
+ /* the data type resulting from this operation is unchanged! */
+ return NULL;
+}
+
+// SYM_REF0(JMPCN_operator_c)
+void *visit(JMPCN_operator_c *symbol) {
+ if (NULL == this->jump_label) ERROR;
+
+ CN_modifier();
+ s4o.print("goto ");
+ this->jump_label->accept(*this);
+ /* the data type resulting from this operation is unchanged! */
+ return NULL;
+}
+
+#if 0
+/*| [NOT] any_identifier SENDTO */
+SYM_REF2(il_assign_out_operator_c, option, variable_name)
+#endif
+
+}; /* generate_cc_il_c */
+
+
+
+
+
+
+
+
+
+/* The implementation of the single visit() member function
+ * of il_default_variable_c.
+ * It can only come after the full declaration of
+ * generate_cc_il_c. Since we define and declare
+ * generate_cc_il_c simultaneously, it can only come
+ * after the definition...
+ */
+void *il_default_variable_c::accept(visitor_c &visitor) {
+ /* An ugly hack!! */
+ /* This is required because we need to over-ride the base
+ * accept(visitor_c &) method of the class symbol_c,
+ * so this method may be called through a symbol_c *
+ * reference!
+ *
+ * But, the visitor_c does not include a visitor to
+ * an il_default_variable_c, which means that we couldn't
+ * simply call visitor.visit(this);
+ *
+ * We therefore need to use the dynamic_cast hack!!
+ *
+ * Note too that we can't cast a visitor_c to a
+ * il_default_variable_visitor_c, since they are not related.
+ * Nor may the il_default_variable_visitor_c inherit from
+ * visitor_c, because then generate_cc_il_c would contain
+ * two visitor_c base classes, one each through
+ * il_default_variable_visitor_c and generate_cc_type_c
+ *
+ * We could use virtual inheritance of the visitor_c, but it
+ * would probably create more problems than it is worth!
+ */
+ generate_cc_il_c *v;
+ v = dynamic_cast<generate_cc_il_c *>(&visitor);
+ if (v == NULL) ERROR;
+
+ return v->visit(this);
+}
+
+
+
+
+il_default_variable_c::il_default_variable_c(const char *var_name_str, symbol_c *current_type) {
+ if (NULL == var_name_str) ERROR;
+ /* Note: current_type may start off with NULL */
+
+ this->var_name = new identifier_c(var_name_str);
+ if (NULL == this->var_name) ERROR;
+
+ this->current_type = current_type;
+}