--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/stage3/flow_control_analysis.cc Wed Aug 22 16:46:17 2012 +0200
@@ -0,0 +1,373 @@
+/*
+ * 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)
+ *
+ */
+
+
+/*
+ * Do flow control analysis of the IEC 61131-3 code.
+ *
+ * We currently only do this for IL code.
+ * This class will annotate the abstract syntax tree, by filling in the
+ * prev_il_instruction variable in the il_instruction_c, so it points to
+ * the previous il_instruction_c object in the instruction list instruction_list_c.
+ *
+ * Since IL code can contain jumps (JMP), the same il_instruction may effectively have
+ * several previous il_instructions. In order to accommodate this, each il_instruction
+ * will maintain a vector (i..e an array) of pointers to all the previous il_instructions.
+ * We do however attempt to guarantee that the first element in the vector (array) will preferentially
+ * point to the il instruction that is right before / imediately preceding the current il instructions,
+ * i.e. the first element in the array will tend to point to the previous il_instruction
+ * that is not a jump JMP IL instruction!
+ *
+ * The result will essentially be a graph of il_instruction_c objects, each
+ * pointing to the previous il_instruction_c object.
+ *
+ * The reality is we will get several independent and isolated linked lists
+ * (actually, since we now process labels correctly, this is really a graph):
+ * one for each block of IL code (e.g. inside a Function, FB or Program).
+ * Additionally, when the IL code has an expression (expression_c object), we will actually
+ * have one more isolated linked list for the IL code inside that expression.
+ *
+ * e.g.
+ * line_1: LD 1
+ * line_2: ADD (42
+ * line_3: ADD B
+ * line_4: ADD C
+ * line_5: )
+ * line_6: ADD D
+ * line_7: ST E
+ *
+ * will result in two independent linked lists:
+ * main list: line_7 -> line_6 -> line2 -> line_1
+ * expr list: lin4_4 -> line_3 -> (operand of line_2, i.e. '42')
+ *
+ *
+ * In the main list, each:
+ * line_x: IL_operation IL_operand
+ * is encoded as
+ * il_instruction_c(label, il_incomplete_instruction)
+ * these il_instruction_c objects will point back to the previous il_instruction_c object.
+ *
+ * In the expr list, each
+ * line_x: IL_operation IL_operand
+ * is encoded as
+ * il_simple_instruction_c(il_simple_instruction)
+ * these il_simple_instruction_c objects will point back to the previous il_simple_instruction_c object,
+ * except the for the first il_simple_instruction_c object in the list, which will point back to
+ * the first il_operand (in the above example, '42'), or NULL is it does not exist.
+ *
+ *
+ * label:
+ * identifier_c
+ *
+ * il_incomplete_instruction:
+ * il_simple_operation (il_simple_operation_c, il_function_call_c)
+ * | il_expression (il_expression_c)
+ * | il_jump_operation (il_jump_operation_c)
+ * | il_fb_call (il_fb_call_c)
+ * | il_formal_funct_call (il_formal_funct_call_c)
+ * | il_return_operator (RET_operator_c, RETC_operator_c, RETCN_operator_c)
+ *
+ *
+ * il_expression_c(il_expr_operator, il_operand, simple_instr_list)
+ *
+ * il_operand:
+ * variable (symbolic_variable_c, direct_variable_c, array_variable_c, structured_variable_c)
+ * | enumerated_value (enumerated_value_c)
+ * | constant (lots of literal classes _c)
+ *
+ * simple_instr_list:
+ * list of il_simple_instruction
+ *
+ * il_simple_instruction:
+ * il_simple_operation (il_simple_operation_c, il_function_call_c)
+ * | il_expression (il_expression_c)
+ * | il_formal_funct_call (il_formal_funct_call_c)
+ *
+ */
+
+#include "flow_control_analysis.hh"
+
+
+
+/* set to 1 to see debug info during execution */
+static int debug = 0;
+
+flow_control_analysis_c::flow_control_analysis_c(symbol_c *ignore) {
+ prev_il_instruction = NULL;
+ curr_il_instruction = NULL;
+}
+
+flow_control_analysis_c::~flow_control_analysis_c(void) {
+}
+
+
+
+/************************************/
+/* B 1.5 Program organization units */
+/************************************/
+/*********************/
+/* B 1.5.1 Functions */
+/*********************/
+void *flow_control_analysis_c::visit(function_declaration_c *symbol) {
+ search_il_label = new search_il_label_c(symbol);
+ if (debug) printf("Doing flow control analysis in body of function %s\n", ((token_c *)(symbol->derived_function_name))->value);
+ symbol->function_body->accept(*this);
+ delete search_il_label;
+ search_il_label = NULL;
+ return NULL;
+}
+
+/***************************/
+/* B 1.5.2 Function blocks */
+/***************************/
+void *flow_control_analysis_c::visit(function_block_declaration_c *symbol) {
+ search_il_label = new search_il_label_c(symbol);
+ if (debug) printf("Doing flow control analysis in body of FB %s\n", ((token_c *)(symbol->fblock_name))->value);
+ symbol->fblock_body->accept(*this);
+ delete search_il_label;
+ search_il_label = NULL;
+ return NULL;
+}
+
+/********************/
+/* B 1.5.3 Programs */
+/********************/
+void *flow_control_analysis_c::visit(program_declaration_c *symbol) {
+ search_il_label = new search_il_label_c(symbol);
+ if (debug) printf("Doing flow control analysis in body of program %s\n", ((token_c *)(symbol->program_type_name))->value);
+ symbol->function_block_body->accept(*this);
+ delete search_il_label;
+ search_il_label = NULL;
+ return NULL;
+}
+
+
+/********************************/
+/* B 1.7 Configuration elements */
+/********************************/
+void *flow_control_analysis_c::visit(configuration_declaration_c *symbol) {
+ return NULL;
+}
+
+
+/****************************************/
+/* B.2 - Language IL (Instruction List) */
+/****************************************/
+/***********************************/
+/* B 2.1 Instructions and Operands */
+/***********************************/
+
+/*| instruction_list il_instruction */
+// SYM_LIST(instruction_list_c)
+void *flow_control_analysis_c::visit(instruction_list_c *symbol) {
+ prev_il_instruction_is_JMP_or_RET = false;
+ for(int i = 0; i < symbol->n; i++) {
+ prev_il_instruction = NULL;
+ if (i > 0) prev_il_instruction = symbol->elements[i-1];
+ curr_il_instruction = symbol->elements[i];
+ curr_il_instruction->accept(*this);
+ curr_il_instruction = NULL;
+ }
+ return NULL;
+}
+
+/* | label ':' [il_incomplete_instruction] eol_list */
+// SYM_REF2(il_instruction_c, label, il_instruction)
+// void *visit(instruction_list_c *symbol);
+void *flow_control_analysis_c::visit(il_instruction_c *symbol) {
+ if ((NULL != prev_il_instruction) && (!prev_il_instruction_is_JMP_or_RET))
+ /* We try to guarantee that the previous il instruction that is in the previous line, will occupy the first element of the vector.
+ * In order to do that, we use insert() instead of push_back()
+ */
+ symbol->prev_il_instruction.insert(symbol->prev_il_instruction.begin() , prev_il_instruction);
+
+ /* check if it is an il_expression_c, a JMP[C[N]], or a RET, and if so, handle it correctly */
+ prev_il_instruction_is_JMP_or_RET = false;
+ if (NULL != symbol->il_instruction)
+ symbol->il_instruction->accept(*this);
+ return NULL;
+}
+
+
+
+/* | il_simple_operator [il_operand] */
+// SYM_REF2(il_simple_operation_c, il_simple_operator, il_operand)
+// void *flow_control_analysis_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 *flow_control_analysis_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 *flow_control_analysis_c::visit(il_expression_c *symbol) {
+ if(NULL == symbol->simple_instr_list)
+ /* nothing to do... */
+ return NULL;
+
+ symbol_c *save_prev_il_instruction = prev_il_instruction;
+ prev_il_instruction = symbol->il_operand;
+ symbol->simple_instr_list->accept(*this);
+ prev_il_instruction = save_prev_il_instruction;
+ return NULL;
+}
+
+
+/* il_jump_operator label */
+// SYM_REF2(il_jump_operation_c, il_jump_operator, label)
+void *flow_control_analysis_c::visit(il_jump_operation_c *symbol) {
+ /* search for the il_instruction_c containing the label */
+ il_instruction_c *destination = search_il_label->find_label(symbol->label);
+
+ /* give the visit(JMP_operator *) an oportunity to set the prev_il_instruction_is_JMP_or_RET flag! */
+ symbol->il_jump_operator->accept(*this);
+ /* add, to that il_instruction's list of prev_il_intsructions, the curr_il_instruction */
+ if (NULL != destination)
+ destination->prev_il_instruction.push_back(curr_il_instruction);
+ return NULL;
+}
+
+
+/* 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 *flow_control_analysis_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 *flow_control_analysis_c::visit(il_formal_funct_call_c *symbol)
+
+
+
+// void *visit(il_operand_list_c *symbol);
+void *flow_control_analysis_c::visit(simple_instr_list_c *symbol) {
+ for(int i = 0; i < symbol->n; i++) {
+ /* The prev_il_instruction for element[0] was set in visit(il_expression_c *) */
+ if (i>0) prev_il_instruction = symbol->elements[i-1];
+ symbol->elements[i]->accept(*this);
+ }
+ return NULL;
+}
+
+
+// SYM_REF1(il_simple_instruction_c, il_simple_instruction, symbol_c *prev_il_instruction;)
+void *flow_control_analysis_c::visit(il_simple_instruction_c*symbol) {
+ if (NULL != prev_il_instruction)
+ /* We try to guarantee that the previous il instruction that is in the previous line, will occupy the first element of the vector.
+ * In order to do that, we use insert() instead of push_back()
+ */
+ symbol->prev_il_instruction.insert(symbol->prev_il_instruction.begin() , prev_il_instruction);
+ return NULL;
+}
+
+
+/*
+ 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);
+
+/* this next visit function will be called directly from visit(il_instruction_c *) */
+void *flow_control_analysis_c::visit( RET_operator_c *symbol) {
+ prev_il_instruction_is_JMP_or_RET = true;
+ return NULL;
+}
+
+// void *visit( RETC_operator_c *symbol);
+// void *visit(RETCN_operator_c *symbol);
+
+/* this next visit function will be called from visit(il_jump_operation_c *) */
+void *flow_control_analysis_c::visit( JMP_operator_c *symbol) {
+ prev_il_instruction_is_JMP_or_RET = true;
+ return NULL;
+}
+
+// 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);
+