--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/stage3/forced_narrow_candidate_datatypes.cc Tue Oct 16 18:01:22 2012 +0100
@@ -0,0 +1,240 @@
+/*
+ * matiec - a compiler for the programming languages defined in IEC 61131-3
+ *
+ * Copyright (C) 2012 Mario de Sousa (msousa@fe.up.pt)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * 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 compiler.
+ *
+ * Based on the
+ * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
+ *
+ */
+
+
+/*
+ * Data type analysis of IL code may leave some IL instructions with an undefined datatype.
+ * This visitor will set the datatype for all these symbols, so that all symbols have a well
+ * defined datatype when we reach stage4.
+ *
+ * Example:
+ * =========
+ *
+ * VAR
+ * N : INT := 99 ;
+ * tonv: TON;
+ * byte_var: BYTE;
+ * tonv : TON;
+ * a : BYTE;
+ * t : time;
+ * tod1: tod;
+ * END_VAR
+ *
+ * (0) --> Data type before executing forced_narrow_candidate_datatypes_c
+ * (1) --> Data type after executing 1st pass of forced_narrow_candidate_datatypes_c
+ * (2) --> Data type after executing 2nd pass of forced_narrow_candidate_datatypes_c
+ *
+ * --- --> NULL (undefined datatype)
+ * *** --> invalid_type_name_c (invalid datatype)
+ *
+ * (0) (1) (2)
+ *
+ * --- *** *** CAL tonv (
+ * PT := T#1s
+ * )
+ * --- *** *** JMP l4
+ *
+ * --- sint sint l0: LD 1
+ * --- sint sint ADD 2
+ * --- (c) sint sint CAL tonv (
+ * PT := T#1s
+ * )
+ *
+ * --- sint sint LD 45
+ * --- (c) sint sint ADD 45
+ *
+ *
+ * --- sint sint LD 3
+ * --- sint sint l1:
+ * --- (c) sint sint l2: ADD 4
+ * int int int LD 5
+ * int int int ST n
+ * int int int JMP l3
+ *
+ * --- (d) --- sint LD 5
+ * --- (d) --- sint SUB 6
+ * --- (d) sint sint JMP l1
+ *
+ * --- bool bool LD FALSE
+ * --- bool bool NOT
+ * --- (b) bool bool RET
+ *
+ * int int int l3:
+ * int int int ST n
+ * --- (b) int int RET
+ *
+ * --- *** *** l4:
+ * --- *** *** CAL tonv (
+ * PT := T#1s
+ * )
+ * --- (a) *** *** JMP l0
+ * --- (b) byte byte LD 88
+ *
+ *
+ *
+ */
+
+
+
+#include "forced_narrow_candidate_datatypes.hh"
+#include "datatype_functions.hh"
+
+
+/* set to 1 to see debug info during execution */
+static int debug = 0;
+
+forced_narrow_candidate_datatypes_c::forced_narrow_candidate_datatypes_c(symbol_c *ignore)
+ :narrow_candidate_datatypes_c(ignore) {
+}
+
+forced_narrow_candidate_datatypes_c::~forced_narrow_candidate_datatypes_c(void) {
+}
+
+
+
+
+
+/****************************************/
+/* B.2 - Language IL (Instruction List) */
+/****************************************/
+/***********************************/
+/* B 2.1 Instructions and Operands */
+/***********************************/
+
+/*| instruction_list il_instruction */
+// SYM_LIST(instruction_list_c)
+void *forced_narrow_candidate_datatypes_c::visit(instruction_list_c *symbol) {
+print_ast_c::print(symbol);
+
+ for(int j = 0; j < 2; j++) {
+ for(int i = symbol->n-1; i >= 0; i--) {
+ symbol->elements[i]->accept(*this);
+ }
+ }
+
+ /* Assert that this algorithm managed to remove all NULL datatypes! */
+ for(int i = symbol->n-1; i >= 0; i--) {
+ if (NULL == symbol->elements[i]->datatype)
+ ERROR;
+ }
+
+ return NULL;
+}
+
+
+
+/* | label ':' [il_incomplete_instruction] eol_list */
+// SYM_REF2(il_instruction_c, label, il_instruction)
+// void *visit(instruction_list_c *symbol);
+void *forced_narrow_candidate_datatypes_c::visit(il_instruction_c *symbol) {
+ if (NULL == symbol->datatype) {
+ if (symbol->candidate_datatypes.empty()) {
+ symbol->datatype = &(search_constant_type_c::invalid_type_name); // This will occur in the situations (a) in the above example
+ // return NULL; // No need to return control to the visit() method of the base class... But we do so, just to be safe (called at the end of this function)!
+ } else {
+ if (symbol->next_il_instruction.empty()) {
+ symbol->datatype = symbol->candidate_datatypes[0]; // This will occur in the situations (b) in the above example
+ } else {
+ symbol_c *next_datatype = NULL;
+
+ /* find the datatype of the following IL instructions (they should all be identical by now, but we don't have an assertion checking for this. */
+ for (unsigned int i=0; i < symbol->next_il_instruction.size(); i++)
+ if (NULL != symbol->next_il_instruction[i]->datatype)
+ next_datatype = symbol->next_il_instruction[i]->datatype;
+ if (get_datatype_info_c::is_type_valid(next_datatype)) {
+ /* This will occur in the following situations from the above example
+ * (d) during the second pass of this algorithm (remember, we execute this algorithm twice, because of backward JMPs!)
+ */
+ symbol->datatype = symbol->candidate_datatypes[0];
+ } else {
+ /* This will occur in the following situations from the above example
+ * (d) during the first pass of this algorithm (remember, we execute this algorithm twice, because of backward JMPs!)
+ */
+ // it is not possible to determine the exact situation in the current pass, so we can't do anything just yet. Leave it for the next time around!
+ }
+ }
+ }
+ }
+
+ /* return control to the visit() method of the base class! */
+ narrow_candidate_datatypes_c::visit(symbol);
+
+ return NULL;
+}
+
+
+
+
+
+/* | il_simple_operator [il_operand] */
+// SYM_REF2(il_simple_operation_c, il_simple_operator, il_operand)
+// void *forced_narrow_candidate_datatypes_c::visit(il_simple_operation_c *symbol)
+
+/* | function_name [il_operand_list] */
+/* NOTE: The parameters 'called_function_declaration' and 'extensible_param_count' are used to pass data between the stage 3 and stage 4. */
+// SYM_REF2(il_function_call_c, function_name, il_operand_list, symbol_c *called_function_declaration; int extensible_param_count;)
+// void *forced_narrow_candidate_datatypes_c::visit(il_function_call_c *symbol)
+
+/* | il_expr_operator '(' [il_operand] eol_list [simple_instr_list] ')' */
+// SYM_REF3(il_expression_c, il_expr_operator, il_operand, simple_instr_list);
+// void *forced_narrow_candidate_datatypes_c::visit(il_expression_c *symbol)
+
+/* il_jump_operator label */
+// SYM_REF2(il_jump_operation_c, il_jump_operator, label)
+// void *forced_narrow_candidate_datatypes_c::visit(il_jump_operation_c *symbol)
+
+/* 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 ')'
+ */
+/* NOTE: The parameter 'called_fb_declaration'is used to pass data between stage 3 and stage4 (although currently it is not used in stage 4 */
+// SYM_REF4(il_fb_call_c, il_call_operator, fb_name, il_operand_list, il_param_list, symbol_c *called_fb_declaration)
+// void *forced_narrow_candidate_datatypes_c::visit(il_fb_call_c *symbol)
+
+/* | function_name '(' eol_list [il_param_list] ')' */
+/* NOTE: The parameter 'called_function_declaration' is used to pass data between the stage 3 and stage 4. */
+// SYM_REF2(il_formal_funct_call_c, function_name, il_param_list, symbol_c *called_function_declaration; int extensible_param_count;)
+// void *forced_narrow_candidate_datatypes_c::visit(il_formal_funct_call_c *symbol)
+
+// void *visit(il_operand_list_c *symbol);
+// void *forced_narrow_candidate_datatypes_c::visit(simple_instr_list_c *symbol)
+
+// SYM_REF1(il_simple_instruction_c, il_simple_instruction, symbol_c *prev_il_instruction;)
+// void *forced_narrow_candidate_datatypes_c::visit(il_simple_instruction_c*symbol)
+
+/*
+ void *visit(il_param_list_c *symbol);
+ void *visit(il_param_assignment_c *symbol);
+ void *visit(il_param_out_assignment_c *symbol);
+ */
+