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/*

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 *  matiec - a compiler for the programming languages defined in IEC 61131-3

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 *

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 *  Copyright (C) 2012  Mario de Sousa (msousa@fe.up.pt)

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 *

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 *  This program is free software: you can redistribute it and/or modify

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 *  it under the terms of the GNU General Public License as published by

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 *  the Free Software Foundation, either version 3 of the License, or

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 *  (at your option) any later version.

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 *

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 *  This program is distributed in the hope that it will be useful,

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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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 *  GNU General Public License for more details.

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 *

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 *  You should have received a copy of the GNU General Public License

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 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.

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 *

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 *

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 * This code is made available on the understanding that it will not be

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 * used in safety-critical situations without a full and competent review.

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 */

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/*

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 * An IEC 61131-3 compiler.

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 *

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 * Based on the

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 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)

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 *

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 */

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/*

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 *  Do flow control analysis of the IEC 61131-3 code.

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 *

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 *  We currently only do this for IL code.

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 *  This class will annotate the abstract syntax tree, by filling in the

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 *  prev_il_instruction variable in the il_instruction_c, so it points to

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 *  the previous il_instruction_c object in the instruction list instruction_list_c.

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 */

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#include "flow_control_analysis.hh"

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/* set to 1 to see debug info during execution */

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static int debug = 0;

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flow_control_analysis_c::flow_control_analysis_c(symbol_c *ignore) {

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}

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flow_control_analysis_c::~flow_control_analysis_c(void) {

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}

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/************************************/

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/* B 1.5 Program organization units */

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/************************************/

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/*********************/

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/* B 1.5.1 Functions */

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/*********************/

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void *flow_control_analysis_c::visit(function_declaration_c *symbol) {

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	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

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	if (debug) printf("Doing flow control analysis in body of function %s\n", ((token_c *)(symbol->derived_function_name))->value);

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	symbol->function_body->accept(*this);

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	delete search_varfb_instance_type;

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	search_varfb_instance_type = NULL;

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	return NULL;

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}

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/***************************/

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/* B 1.5.2 Function blocks */

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/***************************/

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void *flow_control_analysis_c::visit(function_block_declaration_c *symbol) {

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	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

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	if (debug) printf("Doing flow control analysis in body of FB %s\n", ((token_c *)(symbol->fblock_name))->value);

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	symbol->fblock_body->accept(*this);

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	delete search_varfb_instance_type;

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	search_varfb_instance_type = NULL;

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	return NULL;

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}

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/********************/

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/* B 1.5.3 Programs */

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/********************/

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void *flow_control_analysis_c::visit(program_declaration_c *symbol) {

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	search_varfb_instance_type = new search_varfb_instance_type_c(symbol);

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	if (debug) printf("Doing flow control analysis in body of program %s\n", ((token_c *)(symbol->program_type_name))->value);

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	symbol->function_block_body->accept(*this);

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	delete search_varfb_instance_type;

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	search_varfb_instance_type = NULL;

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	return NULL;

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}

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/********************************/

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/* B 1.7 Configuration elements */

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/********************************/

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void *flow_control_analysis_c::visit(configuration_declaration_c *symbol) {

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	return NULL;

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}

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/****************************************/

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/* B.2 - Language IL (Instruction List) */

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/****************************************/

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/***********************************/

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/* B 2.1 Instructions and Operands */

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/***********************************/

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/*| instruction_list il_instruction */

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// SYM_LIST(instruction_list_c)

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void *flow_control_analysis_c::visit(instruction_list_c *symbol) {

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	for(int i = 0; i < symbol->n; i++) {

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		prev_il_instruction = NULL;

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		if (i > 0) prev_il_instruction = symbol->elements[i-1];

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		symbol->elements[i]->accept(*this);

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	}

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	return NULL;

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}

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/* | label ':' [il_incomplete_instruction] eol_list */

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// SYM_REF2(il_instruction_c, label, il_instruction)

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// void *visit(instruction_list_c *symbol);

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void *flow_control_analysis_c::visit(il_instruction_c *symbol) {

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	symbol->prev_il_instruction = prev_il_instruction;

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	/* TODO: handle labels correctly!

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	 *

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	 *      Don't forget to handle multiple consecutive lables too!

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	 *        label3:

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	 *        label4:

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	 *                LD I

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	 */

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	if (NULL != symbol->il_instruction)

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		symbol->il_instruction->accept(*this);

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}

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#if 0

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/* | function_name [il_operand_list] */

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/* NOTE: The parameters 'called_function_declaration' and 'extensible_param_count' are used to pass data between the stage 3 and stage 4. */

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// SYM_REF2(il_function_call_c, function_name, il_operand_list, symbol_c *called_function_declaration; int extensible_param_count;)

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void *flow_control_analysis_c::visit(il_function_call_c *symbol) {

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	return NULL;

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}

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/* | il_expr_operator '(' [il_operand] eol_list [simple_instr_list] ')' */

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// SYM_REF3(il_expression_c, il_expr_operator, il_operand, simple_instr_list);

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void *flow_control_analysis_c::visit(il_expression_c *symbol) {

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/*   il_call_operator prev_declared_fb_name

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 * | il_call_operator prev_declared_fb_name '(' ')'

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 * | il_call_operator prev_declared_fb_name '(' eol_list ')'

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 * | il_call_operator prev_declared_fb_name '(' il_operand_list ')'

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 * | il_call_operator prev_declared_fb_name '(' eol_list il_param_list ')'

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 */

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/* 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 */

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// SYM_REF4(il_fb_call_c, il_call_operator, fb_name, il_operand_list, il_param_list, symbol_c *called_fb_declaration)

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void *flow_control_analysis_c::visit(il_fb_call_c *symbol) {

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	return NULL;

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}

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/* | function_name '(' eol_list [il_param_list] ')' */

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/* NOTE: The parameter 'called_function_declaration' is used to pass data between the stage 3 and stage 4. */

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// SYM_REF2(il_formal_funct_call_c, function_name, il_param_list, symbol_c *called_function_declaration; int extensible_param_count;)

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void *flow_control_analysis_c::visit(il_formal_funct_call_c *symbol) {

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	return NULL;

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}

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#endif

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//  void *visit(il_operand_list_c *symbol);

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void *flow_control_analysis_c::visit(simple_instr_list_c *symbol) {

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		symbol->elements[i]->accept(*this);

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	}

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	return NULL;

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}

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/*

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    void *visit(il_param_list_c *symbol);

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    void *visit(il_param_assignment_c *symbol);

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    void *visit(il_param_out_assignment_c *symbol);

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 */

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