diff -r e657008f43d0 -r da1a8186f86f absyntax_utils/add_en_eno_param_decl.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/absyntax_utils/add_en_eno_param_decl.cc	Thu Aug 27 16:06:46 2009 +0100
@@ -0,0 +1,196 @@
+/*
+ * (c) 2009 Mario de Sousa
+ *
+ * Offered to the public under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2 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.
+ *
+ * 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 IL and ST compiler.
+ *
+ * Based on the
+ * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
+ *
+ */
+
+
+/*
+ * Iterate through all declared functions and Function Blocks, 
+ * and, for each function/FB, add a declaration of the EN and ENO 
+ * parameters, if they have not already been explicitly declared.
+ *
+ * EN and ENO parameters declared explicitly (by the user in the source code)
+ * and implicitly (by the comnpiler, i.e. by this visitor class) may be
+ * distinguished later on by the 'method' flag in the en_param_declaration_c
+ * and eno_param_declaration_c objects.
+ */
+
+#include "add_en_eno_param_decl.hh"
+#include <strings.h>
+
+
+// #define DEBUG
+#ifdef DEBUG
+#define TRACE(classname) printf("\n____%s____\n",classname);
+#else
+#define TRACE(classname)
+#endif
+
+
+#define ERROR error_exit(__FILE__,__LINE__)
+/* function defined in main.cc */
+extern void error_exit(const char *file_name, int line_no);
+
+
+
+/* This class is a singleton.
+ * So we need a pointer to the singe instance...
+ */
+add_en_eno_param_decl_c *add_en_eno_param_decl_c::singleton = NULL;
+
+/* Constructor for the singleton class */
+symbol_c *add_en_eno_param_decl_c::add_to(symbol_c *tree_root) {
+      if (NULL == singleton) {
+        singleton = new add_en_eno_param_decl_c;
+        if (NULL == singleton)
+          return NULL;
+      }
+      tree_root->accept(*singleton);
+      return tree_root;
+    }
+
+/* Destructor for the singleton class */
+add_en_eno_param_decl_c::~add_en_eno_param_decl_c(void) {
+      if (NULL != singleton) delete singleton;
+      singleton = NULL;
+    }
+
+
+
+void* add_en_eno_param_decl_c::iterate_list(list_c *list) {
+  for (int i = 0; i < list->n; i++) {
+    list->elements[i]->accept(*this);
+  }
+  return NULL;
+}
+
+
+input_declarations_c *add_en_eno_param_decl_c::build_en_param(void) {
+  boolean_literal_c *boolean_literal = 
+    new boolean_literal_c(new bool_type_name_c(), new boolean_true_c());
+  identifier_c *identifier =
+    new identifier_c("EN");
+  en_param_declaration_c *en_param_declaration = 
+    new en_param_declaration_c(identifier, new bool_type_name_c(), boolean_literal, new implicit_definition_c());
+    /* the last paramater is to flag that this
+     * declaration was inserted automatically, i.e. an implicit declaration 
+     */
+  input_declaration_list_c *input_declaration_list = new input_declaration_list_c();
+  input_declaration_list->add_element(en_param_declaration);
+
+  input_declarations_c *input_declarations = new input_declarations_c(NULL, input_declaration_list, new implicit_definition_c());
+  return input_declarations;
+}
+
+
+output_declarations_c *add_en_eno_param_decl_c::build_eno_param(void) {
+  identifier_c *identifier =
+    new identifier_c("ENO");
+  eno_param_declaration_c *eno_param_declaration =
+    new eno_param_declaration_c(identifier, new bool_type_name_c(), new implicit_definition_c()); 
+    /* the last paramater is to flag that this
+     * declaration was inserted automatically, i.e. an implicit declaration 
+     */
+  var_init_decl_list_c *var_init_decl_list = new var_init_decl_list_c();
+  var_init_decl_list->add_element(eno_param_declaration);
+
+  output_declarations_c *output_declarations = new output_declarations_c(NULL, var_init_decl_list, new implicit_definition_c());
+  return output_declarations;
+}
+
+
+
+
+/***************************/
+/* B 0 - Programming Model */
+/***************************/
+void *add_en_eno_param_decl_c::visit(library_c *symbol) {
+  TRACE("library_c"); 
+  return iterate_list(symbol);
+}
+
+
+/***********************/
+/* B 1.5.1 - Functions */
+/***********************/
+void *add_en_eno_param_decl_c::visit(function_declaration_c *symbol) {
+  TRACE("function_declaration_c"); 
+  return symbol->var_declarations_list->accept(*this);
+}
+
+void *add_en_eno_param_decl_c::visit(var_declarations_list_c *symbol) {
+    TRACE("var_declarations_list_c");
+    en_declared  = false; 
+    eno_declared = false; 
+    iterate_list(symbol);
+    if(en_declared  == false) symbol->add_element(build_en_param());
+    if(eno_declared == false) symbol->add_element(build_eno_param());
+    return NULL;
+}
+
+
+
+/****************************************/
+/* 1.4.3 - Declaration & Initialisation */
+/****************************************/
+void *add_en_eno_param_decl_c::visit(input_declarations_c *symbol) {
+  TRACE("input_declarations_c");
+//   current_param_direction = direction_in;
+  return symbol->input_declaration_list->accept(*this);
+}
+
+void *add_en_eno_param_decl_c::visit(input_declaration_list_c *symbol) {TRACE("input_declaration_list_c"); return iterate_list(symbol);}
+
+void *add_en_eno_param_decl_c::visit(en_param_declaration_c *symbol) {
+  TRACE("en_param_declaration_c");
+  en_declared = true;
+  return NULL;
+}
+
+void *add_en_eno_param_decl_c::visit(eno_param_declaration_c *symbol) {
+  TRACE("eno_param_declaration_c");
+  eno_declared = true;
+  return NULL;
+}
+
+void *add_en_eno_param_decl_c::visit(output_declarations_c *symbol) {
+  TRACE("output_declarations_c");
+//   current_param_direction = direction_out;
+  return symbol->var_init_decl_list->accept(*this);
+}
+
+void *add_en_eno_param_decl_c::visit(var_init_decl_list_c *symbol) 
+{TRACE("var_init_decl_list_c"); return iterate_list(symbol);}
+
+
+/*****************************/
+/* B 1.5.2 - Function Blocks */
+/*****************************/
+/*  FUNCTION_BLOCK derived_function_block_name io_OR_other_var_declarations function_block_body END_FUNCTION_BLOCK */
+void *add_en_eno_param_decl_c::visit(function_block_declaration_c *symbol) {
+  TRACE("function_block_declaration_c"); 
+  return symbol->var_declarations->accept(*this);
+}
+
+
+
+