/*
* 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);
*/