--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/stage3/visit_expression_type.hh Thu Aug 27 16:29:23 2009 +0100
@@ -0,0 +1,294 @@
+/*
+ * (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)
+ *
+ */
+
+/* Verify whether the semantic rules of data type compatibility are being followed.
+ *
+ * For example:
+ */
+
+#include "../absyntax_utils/absyntax_utils.hh"
+
+class visit_expression_type_c: public search_constant_type_c {
+
+ private:
+ search_varfb_instance_type_c *search_varfb_instance_type;
+ search_base_type_c search_base_type;
+
+ /* 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 bject instance is instantiated whenever we start checking semantics
+ * 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_var_instance_decl_c *search_var_instance_decl;
+
+ /* This variable was created to pass information from
+ * visit_expression_type_c::visit(case_statement_c *symbol) function to
+ * visit_expression_type_c::visit(case_list_c *symbol) function.
+ */
+ symbol_c *case_expression_type;
+
+ /* In IL code, once we find a type mismatch error, it is best to
+ * ignore any further errors until the end of the logicl operation,
+ * i.e. until the next LD.
+ * However, we cannot clear the il_error flag on all LD operations,
+ * as these may also be used within parenthesis. LD operations
+ * within parenthesis may not clear the error flag.
+ * We therefore need a counter to know how deep inside a parenthesis
+ * structure we are.
+ */
+ int il_parenthesis_level;
+ bool il_error;
+
+ symbol_c *il_default_variable_type;
+ symbol_c *il_operand_type;
+
+
+ public:
+ visit_expression_type_c(symbol_c *search_scope);
+ virtual ~visit_expression_type_c(void);
+
+ /* A helper function... */
+ bool is_ANY_ELEMENTARY_type(symbol_c *type_symbol);
+ bool is_ANY_MAGNITUDE_type(symbol_c *type_symbol);
+ bool is_ANY_DATE_type(symbol_c *type_symbol);
+ bool is_ANY_STRING_type(symbol_c *type_symbol);
+ bool is_ANY_INT_type(symbol_c *type_symbol);
+ bool is_ANY_REAL_type(symbol_c *type_symbol);
+ bool is_ANY_NUM_type(symbol_c *type_symbol);
+ bool is_ANY_BIT_type(symbol_c *type_symbol);
+ bool is_BOOL_type(symbol_c *type_symbol);
+
+ bool is_literal_integer_type(symbol_c *type_symbol);
+ bool is_literal_real_type(symbol_c *type_symbol);
+ bool is_literal_bool_type(symbol_c *type_symbol);
+
+ /* Determine the common data type between two data types.
+ * If no common data type found, return NULL.
+ *
+ * If data types are identical, return the first (any would do...).
+ * If any of the datat types is a literal, we confirm that
+ * the literal uses less bits than the fixed size data type.
+ * e.g. BYTE and 1024 returns NULL
+ * BYTE and 255 returns BYTE
+ *
+ * If two literals, then return the literal that requires more bits...
+ */
+ symbol_c *common_type__(symbol_c *first_type, symbol_c *second_type);
+ /* Determine the common data type between two data types.
+ * Unlike the common_type__() function, we stop the compiler with an ERROR
+ * if no common data type is found.
+ */
+ symbol_c *common_type(symbol_c *first_type, symbol_c *second_type);
+ /* Return TRUE if there is a common data type, otherwise return FALSE */
+ bool is_compatible_type(symbol_c *first_type, symbol_c *second_type);
+
+ void compute_input_operatores(symbol_c *symbol, const char *input_operator);
+ void check_formal_parameter(symbol_c *call_param_name, symbol_c *call_param_type, symbol_c *f_decl);
+
+ /* check the semantics of a FB or Function non-formal call */
+ /* e.g. foo(1, 2, 3, 4); */
+ void check_nonformal_call(symbol_c *f_call, symbol_c *f_decl, bool use_il_defvar = false);
+ /* check the semantics of a FB or Function formal call */
+ /* e.g. foo(IN1 := 1, OUT1 =>x, EN := true); */
+ void check_formal_call(symbol_c *f_call, symbol_c *f_decl);
+
+
+ void *compute_standard_function_default(function_invocation_c *st_symbol, il_formal_funct_call_c *il_symbol);
+ void *compute_standard_function_il(il_function_call_c *symbol, symbol_c *param_data_type);
+
+
+ /* A helper function... */
+ typedef bool (visit_expression_type_c::*is_data_type_t)(symbol_c *type_symbol); /* a pointer to a function! */
+ symbol_c *compute_boolean_expression(symbol_c *left_exp, symbol_c *right_exp, is_data_type_t is_data_type);
+ symbol_c *compute_numeric_expression(symbol_c *left_exp, symbol_c *right_exp, is_data_type_t is_data_type);
+
+ /* a helper function... */
+ symbol_c *base_type(symbol_c *symbol);
+
+ /* a helper function... */
+ void *verify_null(symbol_c *symbol);
+
+
+
+
+ /*********************/
+ /* B 1.4 - Variables */
+ /*********************/
+ void *visit(symbolic_variable_c *symbol);
+
+ /********************************************/
+ /* B 1.4.1 - Directly Represented Variables */
+ /********************************************/
+ void *visit(direct_variable_c *symbol);
+
+ /*************************************/
+ /* B 1.4.2 - Multi-element variables */
+ /*************************************/
+
+ void *visit(array_variable_c *symbol);
+ void *visit(structured_variable_c *symbol);
+
+ /****************************************/
+ /* B.2 - Language IL (Instruction List) */
+ /****************************************/
+ /***********************************/
+ /* B 2.1 Instructions and Operands */
+ /***********************************/
+ // void *visit(instruction_list_c *symbol);
+ void *visit(il_simple_operation_c *symbol);
+ void *visit(il_function_call_c *symbol);
+ void *visit(il_expression_c *symbol);
+// void *visit(il_jump_operation_c *symbol);
+ void *visit(il_fb_call_c *symbol);
+ void *visit(il_formal_funct_call_c *symbol);
+ /*
+ void *visit(il_operand_list_c *symbol);
+ void *visit(simple_instr_list_c *symbol);
+ void *visit(il_param_list_c *symbol);
+ void *visit(il_param_assignment_c *symbol);
+ void *visit(il_param_out_assignment_c *symbol);
+ */
+
+ /*******************/
+ /* B 2.2 Operators */
+ /*******************/
+ void *visit(LD_operator_c *symbol);
+ void *visit(LDN_operator_c *symbol);
+ void *visit(ST_operator_c *symbol);
+ void *visit(STN_operator_c *symbol);
+ void *visit(NOT_operator_c *symbol);
+ void *visit(S_operator_c *symbol);
+ void *visit(R_operator_c *symbol);
+ void *visit(S1_operator_c *symbol);
+ void *visit(R1_operator_c *symbol);
+ void *visit(CLK_operator_c *symbol);
+ void *visit(CU_operator_c *symbol);
+ void *visit(CD_operator_c *symbol);
+ void *visit(PV_operator_c *symbol);
+ void *visit(IN_operator_c *symbol);
+ void *visit(PT_operator_c *symbol);
+ void *visit(AND_operator_c *symbol);
+ void *visit(OR_operator_c *symbol);
+ void *visit(XOR_operator_c *symbol);
+ void *visit(ANDN_operator_c *symbol);
+ void *visit(ORN_operator_c *symbol);
+ void *visit(XORN_operator_c *symbol);
+ void *visit(ADD_operator_c *symbol);
+ void *visit(SUB_operator_c *symbol);
+ void *visit(MUL_operator_c *symbol);
+ void *visit(DIV_operator_c *symbol);
+ void *visit(MOD_operator_c *symbol);
+ void *visit(GT_operator_c *symbol);
+ void *visit(GE_operator_c *symbol);
+ void *visit(EQ_operator_c *symbol);
+ void *visit(LT_operator_c *symbol);
+ void *visit(LE_operator_c *symbol);
+ void *visit(NE_operator_c *symbol);
+ void *visit(CAL_operator_c *symbol);
+ void *visit(CALC_operator_c *symbol);
+ void *visit(CALCN_operator_c *symbol);
+ void *visit(RET_operator_c *symbol);
+ void *visit(RETC_operator_c *symbol);
+ void *visit(RETCN_operator_c *symbol);
+ void *visit(JMP_operator_c *symbol);
+ void *visit(JMPC_operator_c *symbol);
+ void *visit(JMPCN_operator_c *symbol);
+ /* Symbol class handled together with function call checks */
+ // void *visit(il_assign_operator_c *symbol, variable_name);
+ /* Symbol class handled together with function call checks */
+ // void *visit(il_assign_operator_c *symbol, option, variable_name);
+
+
+
+ /***************************************/
+ /* B.3 - Language ST (Structured Text) */
+ /***************************************/
+ /***********************/
+ /* B 3.1 - Expressions */
+ /***********************/
+ void *visit(or_expression_c *symbol);
+ void *visit(xor_expression_c *symbol);
+ void *visit(and_expression_c *symbol);
+ void *visit(equ_expression_c *symbol);
+ void *visit(notequ_expression_c *symbol);
+ void *visit(lt_expression_c *symbol);
+ void *visit(gt_expression_c *symbol);
+ void *visit(le_expression_c *symbol);
+ void *visit(ge_expression_c *symbol);
+ void *visit(add_expression_c *symbol);
+ void *visit(sub_expression_c *symbol);
+ void *visit(mul_expression_c *symbol);
+ void *visit(div_expression_c *symbol);
+ void *visit(mod_expression_c *symbol);
+ void *visit(power_expression_c *symbol);
+ void *visit(neg_expression_c *symbol);
+ void *visit(not_expression_c *symbol);
+ void *visit(function_invocation_c *symbol);
+
+ /*********************************/
+ /* B 3.2.1 Assignment Statements */
+ /*********************************/
+ void *visit(assignment_statement_c *symbol);
+
+ /*****************************************/
+ /* B 3.2.2 Subprogram Control Statements */
+ /*****************************************/
+ void *visit(fb_invocation_c *symbol);
+
+ /********************************/
+ /* B 3.2.3 Selection Statements */
+ /********************************/
+
+ void *visit(if_statement_c *symbol);
+// void *visit(elseif_statement_list_c *symbol);
+ void *visit(elseif_statement_c *symbol);
+ void *visit(case_statement_c *symbol);
+// void *visit(case_element_list_c *symbol);
+// void *visit(case_element_c *symbol);
+ void *visit(case_list_c *symbol);
+
+ /********************************/
+ /* B 3.2.4 Iteration Statements */
+ /********************************/
+
+ void *visit(for_statement_c *symbol);
+ void *visit(while_statement_c *symbol);
+ void *visit(repeat_statement_c *symbol);
+
+
+//TODO: delete this functions. Why are they needed?
+void *visit(program_declaration_c *symbol);
+void *visit(function_declaration_c *symbol);
+void *visit(function_block_declaration_c *symbol);
+
+}; // visit_expression_type_c
+