msousa@443: /*
msousa@443: * matiec - a compiler for the programming languages defined in IEC 61131-3
msousa@443: *
msousa@443: * Copyright (C) 2012 Mario de Sousa (msousa@fe.up.pt)
msousa@443: *
msousa@443: * This program is free software: you can redistribute it and/or modify
msousa@443: * it under the terms of the GNU General Public License as published by
msousa@443: * the Free Software Foundation, either version 3 of the License, or
msousa@443: * (at your option) any later version.
msousa@443: *
msousa@443: * This program is distributed in the hope that it will be useful,
msousa@443: * but WITHOUT ANY WARRANTY; without even the implied warranty of
msousa@443: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
msousa@443: * GNU General Public License for more details.
msousa@443: *
msousa@443: * You should have received a copy of the GNU General Public License
msousa@443: * along with this program. If not, see .
msousa@443: *
msousa@443: *
msousa@443: * This code is made available on the understanding that it will not be
msousa@443: * used in safety-critical situations without a full and competent review.
msousa@443: */
msousa@443:
msousa@443: /*
msousa@443: * An IEC 61131-3 compiler.
msousa@443: *
msousa@443: * Based on the
msousa@443: * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
msousa@443: *
msousa@443: */
msousa@443:
msousa@443:
msousa@443: /*
msousa@443: * Do flow control analysis of the IEC 61131-3 code.
msousa@443: *
msousa@443: * We currently only do this for IL code.
msousa@443: * This class will annotate the abstract syntax tree, by filling in the
msousa@443: * prev_il_instruction variable in the il_instruction_c, so it points to
msousa@443: * the previous il_instruction_c object in the instruction list instruction_list_c.
msousa@453: *
msousa@486: * Since IL code can contain jumps (JMP), the same il_instruction may effectively have
msousa@486: * several previous il_instructions. In order to accommodate this, each il_instruction
msousa@486: * will maintain a vector (i..e an array) of pointers to all the previous il_instructions.
msousa@486: * We do however attempt to guarantee that the first element in the vector (array) will preferentially
msousa@486: * point to the il instruction that is right before / imediately preceding the current il instructions,
msousa@486: * i.e. the first element in the array will tend to point to the previous il_instruction
msousa@486: * that is not a jump JMP IL instruction!
msousa@486: *
msousa@486: * The result will essentially be a graph of il_instruction_c objects, each
msousa@453: * pointing to the previous il_instruction_c object.
msousa@453: *
msousa@453: * The reality is we will get several independent and isolated linked lists
msousa@486: * (actually, since we now process labels correctly, this is really a graph):
msousa@453: * one for each block of IL code (e.g. inside a Function, FB or Program).
msousa@453: * Additionally, when the IL code has an expression (expression_c object), we will actually
msousa@453: * have one more isolated linked list for the IL code inside that expression.
msousa@453: *
msousa@453: * e.g.
msousa@453: * line_1: LD 1
msousa@453: * line_2: ADD (42
msousa@453: * line_3: ADD B
msousa@453: * line_4: ADD C
msousa@453: * line_5: )
msousa@453: * line_6: ADD D
msousa@453: * line_7: ST E
msousa@453: *
msousa@453: * will result in two independent linked lists:
msousa@453: * main list: line_7 -> line_6 -> line2 -> line_1
msousa@453: * expr list: lin4_4 -> line_3 -> (operand of line_2, i.e. '42')
msousa@453: *
msousa@453: *
msousa@453: * In the main list, each:
msousa@453: * line_x: IL_operation IL_operand
msousa@453: * is encoded as
msousa@453: * il_instruction_c(label, il_incomplete_instruction)
msousa@453: * these il_instruction_c objects will point back to the previous il_instruction_c object.
msousa@453: *
msousa@453: * In the expr list, each
msousa@453: * line_x: IL_operation IL_operand
msousa@453: * is encoded as
msousa@453: * il_simple_instruction_c(il_simple_instruction)
msousa@453: * these il_simple_instruction_c objects will point back to the previous il_simple_instruction_c object,
msousa@453: * except the for the first il_simple_instruction_c object in the list, which will point back to
msousa@453: * the first il_operand (in the above example, '42'), or NULL is it does not exist.
msousa@453: *
msousa@453: *
msousa@453: * label:
msousa@453: * identifier_c
msousa@453: *
msousa@453: * il_incomplete_instruction:
msousa@453: * il_simple_operation (il_simple_operation_c, il_function_call_c)
msousa@453: * | il_expression (il_expression_c)
msousa@453: * | il_jump_operation (il_jump_operation_c)
msousa@453: * | il_fb_call (il_fb_call_c)
msousa@453: * | il_formal_funct_call (il_formal_funct_call_c)
msousa@453: * | il_return_operator (RET_operator_c, RETC_operator_c, RETCN_operator_c)
msousa@453: *
msousa@453: *
msousa@453: * il_expression_c(il_expr_operator, il_operand, simple_instr_list)
msousa@453: *
msousa@453: * il_operand:
msousa@453: * variable (symbolic_variable_c, direct_variable_c, array_variable_c, structured_variable_c)
msousa@453: * | enumerated_value (enumerated_value_c)
msousa@453: * | constant (lots of literal classes _c)
msousa@453: *
msousa@453: * simple_instr_list:
msousa@453: * list of il_simple_instruction
msousa@453: *
msousa@453: * il_simple_instruction:
msousa@454: * il_simple_operation (il_simple_operation_c, il_function_call_c)
msousa@453: * | il_expression (il_expression_c)
msousa@453: * | il_formal_funct_call (il_formal_funct_call_c)
msousa@453: *
msousa@443: */
msousa@443:
msousa@443: #include "flow_control_analysis.hh"
msousa@443:
msousa@443:
msousa@443:
msousa@443: /* set to 1 to see debug info during execution */
msousa@443: static int debug = 0;
msousa@443:
msousa@443: flow_control_analysis_c::flow_control_analysis_c(symbol_c *ignore) {
msousa@459: prev_il_instruction = NULL;
msousa@459: curr_il_instruction = NULL;
conti@661: prev_il_instruction_is_JMP_or_RET = false;
conti@661: search_il_label = NULL;
msousa@443: }
msousa@443:
msousa@443: flow_control_analysis_c::~flow_control_analysis_c(void) {
msousa@443: }
msousa@443:
msousa@443:
msousa@672: void flow_control_analysis_c::link_insert(symbol_c *prev_instruction, symbol_c *next_instruction) {
msousa@685: il_instruction_c *next_a = dynamic_cast(next_instruction);
msousa@685: il_instruction_c *prev_a = dynamic_cast(prev_instruction);
msousa@685: il_simple_instruction_c *next_b = dynamic_cast(next_instruction);
msousa@685: il_simple_instruction_c *prev_b = dynamic_cast(prev_instruction);
msousa@685:
msousa@685: if (NULL != next_a) next_a->prev_il_instruction.insert(next_a->prev_il_instruction.begin(), prev_instruction);
msousa@685: else if (NULL != next_b) next_b->prev_il_instruction.insert(next_b->prev_il_instruction.begin(), prev_instruction);
msousa@685: else ERROR;
msousa@685:
msousa@685: if (NULL != prev_a) prev_a->next_il_instruction.insert(prev_a->next_il_instruction.begin(), next_instruction);
msousa@685: else if (NULL != prev_b) prev_b->next_il_instruction.insert(prev_b->next_il_instruction.begin(), next_instruction);
msousa@685: else ERROR;
msousa@672: }
msousa@672:
msousa@672:
msousa@672: void flow_control_analysis_c::link_pushback(symbol_c *prev_instruction, symbol_c *next_instruction) {
msousa@672: il_instruction_c *next = dynamic_cast(next_instruction);
msousa@672: il_instruction_c *prev = dynamic_cast(prev_instruction);
msousa@672: if ((NULL == next) || (NULL == prev)) ERROR;
msousa@672:
msousa@672: next->prev_il_instruction.push_back(prev);
msousa@672: prev->next_il_instruction.push_back(next);
msousa@672: }
msousa@672:
msousa@443:
msousa@443: /************************************/
msousa@443: /* B 1.5 Program organization units */
msousa@443: /************************************/
msousa@443: /*********************/
msousa@443: /* B 1.5.1 Functions */
msousa@443: /*********************/
msousa@443: void *flow_control_analysis_c::visit(function_declaration_c *symbol) {
msousa@459: search_il_label = new search_il_label_c(symbol);
msousa@443: if (debug) printf("Doing flow control analysis in body of function %s\n", ((token_c *)(symbol->derived_function_name))->value);
msousa@443: symbol->function_body->accept(*this);
msousa@459: delete search_il_label;
msousa@459: search_il_label = NULL;
msousa@443: return NULL;
msousa@443: }
msousa@443:
msousa@443: /***************************/
msousa@443: /* B 1.5.2 Function blocks */
msousa@443: /***************************/
msousa@443: void *flow_control_analysis_c::visit(function_block_declaration_c *symbol) {
msousa@459: search_il_label = new search_il_label_c(symbol);
msousa@443: if (debug) printf("Doing flow control analysis in body of FB %s\n", ((token_c *)(symbol->fblock_name))->value);
msousa@443: symbol->fblock_body->accept(*this);
msousa@459: delete search_il_label;
msousa@459: search_il_label = NULL;
msousa@443: return NULL;
msousa@443: }
msousa@443:
msousa@443: /********************/
msousa@443: /* B 1.5.3 Programs */
msousa@443: /********************/
msousa@443: void *flow_control_analysis_c::visit(program_declaration_c *symbol) {
msousa@459: search_il_label = new search_il_label_c(symbol);
msousa@443: if (debug) printf("Doing flow control analysis in body of program %s\n", ((token_c *)(symbol->program_type_name))->value);
msousa@443: symbol->function_block_body->accept(*this);
msousa@459: delete search_il_label;
msousa@459: search_il_label = NULL;
msousa@443: return NULL;
msousa@443: }
msousa@443:
msousa@443:
msousa@443: /********************************/
msousa@443: /* B 1.7 Configuration elements */
msousa@443: /********************************/
msousa@443: void *flow_control_analysis_c::visit(configuration_declaration_c *symbol) {
msousa@443: return NULL;
msousa@443: }
msousa@443:
msousa@443:
msousa@443: /****************************************/
msousa@443: /* B.2 - Language IL (Instruction List) */
msousa@443: /****************************************/
msousa@443: /***********************************/
msousa@443: /* B 2.1 Instructions and Operands */
msousa@443: /***********************************/
msousa@443:
msousa@443: /*| instruction_list il_instruction */
msousa@443: // SYM_LIST(instruction_list_c)
msousa@443: void *flow_control_analysis_c::visit(instruction_list_c *symbol) {
msousa@463: prev_il_instruction_is_JMP_or_RET = false;
msousa@448: for(int i = 0; i < symbol->n; i++) {
msousa@448: prev_il_instruction = NULL;
msousa@448: if (i > 0) prev_il_instruction = symbol->elements[i-1];
msousa@459: curr_il_instruction = symbol->elements[i];
msousa@459: curr_il_instruction->accept(*this);
msousa@459: curr_il_instruction = NULL;
msousa@443: }
msousa@443: return NULL;
msousa@443: }
msousa@443:
msousa@443: /* | label ':' [il_incomplete_instruction] eol_list */
msousa@443: // SYM_REF2(il_instruction_c, label, il_instruction)
msousa@443: // void *visit(instruction_list_c *symbol);
msousa@443: void *flow_control_analysis_c::visit(il_instruction_c *symbol) {
msousa@463: if ((NULL != prev_il_instruction) && (!prev_il_instruction_is_JMP_or_RET))
msousa@486: /* We try to guarantee that the previous il instruction that is in the previous line, will occupy the first element of the vector.
msousa@486: * In order to do that, we use insert() instead of push_back()
msousa@486: */
msousa@672: link_insert(prev_il_instruction, symbol);
msousa@459:
msousa@463: /* check if it is an il_expression_c, a JMP[C[N]], or a RET, and if so, handle it correctly */
msousa@463: prev_il_instruction_is_JMP_or_RET = false;
msousa@452: if (NULL != symbol->il_instruction)
msousa@452: symbol->il_instruction->accept(*this);
msousa@453: return NULL;
msousa@443: }
msousa@443:
msousa@443:
msousa@459:
msousa@459: /* | il_simple_operator [il_operand] */
msousa@459: // SYM_REF2(il_simple_operation_c, il_simple_operator, il_operand)
msousa@459: // void *flow_control_analysis_c::visit(il_simple_operation_c *symbol)
msousa@459:
msousa@459:
msousa@459:
msousa@443: /* | function_name [il_operand_list] */
msousa@443: /* NOTE: The parameters 'called_function_declaration' and 'extensible_param_count' are used to pass data between the stage 3 and stage 4. */
msousa@443: // SYM_REF2(il_function_call_c, function_name, il_operand_list, symbol_c *called_function_declaration; int extensible_param_count;)
msousa@459: // void *flow_control_analysis_c::visit(il_function_call_c *symbol)
msousa@459:
msousa@443:
msousa@443: /* | il_expr_operator '(' [il_operand] eol_list [simple_instr_list] ')' */
msousa@443: // SYM_REF3(il_expression_c, il_expr_operator, il_operand, simple_instr_list);
msousa@443: void *flow_control_analysis_c::visit(il_expression_c *symbol) {
msousa@453: if(NULL == symbol->simple_instr_list)
msousa@453: /* nothing to do... */
msousa@453: return NULL;
msousa@453:
msousa@459: symbol_c *save_prev_il_instruction = prev_il_instruction;
msousa@453: prev_il_instruction = symbol->il_operand;
msousa@453: symbol->simple_instr_list->accept(*this);
msousa@459: prev_il_instruction = save_prev_il_instruction;
msousa@459: return NULL;
msousa@459: }
msousa@459:
msousa@459:
msousa@459: /* il_jump_operator label */
msousa@459: // SYM_REF2(il_jump_operation_c, il_jump_operator, label)
msousa@459: void *flow_control_analysis_c::visit(il_jump_operation_c *symbol) {
msousa@459: /* search for the il_instruction_c containing the label */
msousa@459: il_instruction_c *destination = search_il_label->find_label(symbol->label);
msousa@459:
msousa@463: /* give the visit(JMP_operator *) an oportunity to set the prev_il_instruction_is_JMP_or_RET flag! */
msousa@463: symbol->il_jump_operator->accept(*this);
msousa@459: if (NULL != destination)
msousa@672: link_pushback(curr_il_instruction, destination);
msousa@459: return NULL;
msousa@459: }
msousa@459:
msousa@459:
msousa@443: /* il_call_operator prev_declared_fb_name
msousa@443: * | il_call_operator prev_declared_fb_name '(' ')'
msousa@443: * | il_call_operator prev_declared_fb_name '(' eol_list ')'
msousa@443: * | il_call_operator prev_declared_fb_name '(' il_operand_list ')'
msousa@443: * | il_call_operator prev_declared_fb_name '(' eol_list il_param_list ')'
msousa@443: */
msousa@443: /* 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 */
msousa@443: // SYM_REF4(il_fb_call_c, il_call_operator, fb_name, il_operand_list, il_param_list, symbol_c *called_fb_declaration)
msousa@459: // void *flow_control_analysis_c::visit(il_fb_call_c *symbol)
msousa@443:
msousa@443:
msousa@443: /* | function_name '(' eol_list [il_param_list] ')' */
msousa@443: /* NOTE: The parameter 'called_function_declaration' is used to pass data between the stage 3 and stage 4. */
msousa@443: // SYM_REF2(il_formal_funct_call_c, function_name, il_param_list, symbol_c *called_function_declaration; int extensible_param_count;)
msousa@459: // void *flow_control_analysis_c::visit(il_formal_funct_call_c *symbol)
msousa@459:
msousa@443:
msousa@443:
msousa@452: // void *visit(il_operand_list_c *symbol);
msousa@452: void *flow_control_analysis_c::visit(simple_instr_list_c *symbol) {
msousa@454: for(int i = 0; i < symbol->n; i++) {
msousa@453: /* The prev_il_instruction for element[0] was set in visit(il_expression_c *) */
msousa@453: if (i>0) prev_il_instruction = symbol->elements[i-1];
msousa@452: symbol->elements[i]->accept(*this);
msousa@452: }
msousa@452: return NULL;
msousa@452: }
msousa@452:
msousa@453:
msousa@453: // SYM_REF1(il_simple_instruction_c, il_simple_instruction, symbol_c *prev_il_instruction;)
msousa@453: void *flow_control_analysis_c::visit(il_simple_instruction_c*symbol) {
msousa@459: if (NULL != prev_il_instruction)
msousa@486: /* We try to guarantee that the previous il instruction that is in the previous line, will occupy the first element of the vector.
msousa@486: * In order to do that, we use insert() instead of push_back()
msousa@486: */
msousa@672: link_insert(prev_il_instruction, symbol);
msousa@672:
msousa@453: return NULL;
msousa@453: }
msousa@453:
msousa@453:
msousa@443: /*
msousa@443: void *visit(il_param_list_c *symbol);
msousa@443: void *visit(il_param_assignment_c *symbol);
msousa@443: void *visit(il_param_out_assignment_c *symbol);
msousa@443: */
msousa@443:
msousa@443:
msousa@443:
msousa@459:
msousa@459: /*******************/
msousa@459: /* B 2.2 Operators */
msousa@459: /*******************/
msousa@459: // void *visit( LD_operator_c *symbol);
msousa@459: // void *visit( LDN_operator_c *symbol);
msousa@459: // void *visit( ST_operator_c *symbol);
msousa@459: // void *visit( STN_operator_c *symbol);
msousa@459: // void *visit( NOT_operator_c *symbol);
msousa@459: // void *visit( S_operator_c *symbol);
msousa@459: // void *visit( R_operator_c *symbol);
msousa@459: // void *visit( S1_operator_c *symbol);
msousa@459: // void *visit( R1_operator_c *symbol);
msousa@459: // void *visit( CLK_operator_c *symbol);
msousa@459: // void *visit( CU_operator_c *symbol);
msousa@459: // void *visit( CD_operator_c *symbol);
msousa@459: // void *visit( PV_operator_c *symbol);
msousa@459: // void *visit( IN_operator_c *symbol);
msousa@459: // void *visit( PT_operator_c *symbol);
msousa@459: // void *visit( AND_operator_c *symbol);
msousa@459: // void *visit( OR_operator_c *symbol);
msousa@459: // void *visit( XOR_operator_c *symbol);
msousa@459: // void *visit( ANDN_operator_c *symbol);
msousa@459: // void *visit( ORN_operator_c *symbol);
msousa@459: // void *visit( XORN_operator_c *symbol);
msousa@459: // void *visit( ADD_operator_c *symbol);
msousa@459: // void *visit( SUB_operator_c *symbol);
msousa@459: // void *visit( MUL_operator_c *symbol);
msousa@459: // void *visit( DIV_operator_c *symbol);
msousa@459: // void *visit( MOD_operator_c *symbol);
msousa@459: // void *visit( GT_operator_c *symbol);
msousa@459: // void *visit( GE_operator_c *symbol);
msousa@459: // void *visit( EQ_operator_c *symbol);
msousa@459: // void *visit( LT_operator_c *symbol);
msousa@459: // void *visit( LE_operator_c *symbol);
msousa@459: // void *visit( NE_operator_c *symbol);
msousa@459: // void *visit( CAL_operator_c *symbol);
msousa@459: // void *visit( CALC_operator_c *symbol);
msousa@459: // void *visit(CALCN_operator_c *symbol);
msousa@463:
msousa@463: /* this next visit function will be called directly from visit(il_instruction_c *) */
msousa@463: void *flow_control_analysis_c::visit( RET_operator_c *symbol) {
msousa@463: prev_il_instruction_is_JMP_or_RET = true;
msousa@463: return NULL;
msousa@463: }
msousa@463:
msousa@459: // void *visit( RETC_operator_c *symbol);
msousa@459: // void *visit(RETCN_operator_c *symbol);
msousa@463:
msousa@463: /* this next visit function will be called from visit(il_jump_operation_c *) */
msousa@463: void *flow_control_analysis_c::visit( JMP_operator_c *symbol) {
msousa@463: prev_il_instruction_is_JMP_or_RET = true;
msousa@463: return NULL;
msousa@463: }
msousa@463:
msousa@459: // void *visit( JMPC_operator_c *symbol);
msousa@459: // void *visit(JMPCN_operator_c *symbol);
msousa@459:
msousa@459: /* Symbol class handled together with function call checks */
msousa@459: // void *visit(il_assign_operator_c *symbol, variable_name);
msousa@459: /* Symbol class handled together with function call checks */
msousa@459: // void *visit(il_assign_operator_c *symbol, option, variable_name);
msousa@459: