absyntax_utils/array_dimension_iterator.cc
changeset 377 60b012b7793f
child 562 044238931066
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/absyntax_utils/array_dimension_iterator.cc	Wed Sep 14 22:58:39 2011 +0200
@@ -0,0 +1,139 @@
+/*
+ *  matiec - a compiler for the programming languages defined in IEC 61131-3
+ *
+ *  Copyright (C) 2003-2011  Mario de Sousa (msousa@fe.up.pt)
+ *  Copyright (C) 2007-2011  Laurent Bessard and Edouard Tisserant
+ *
+ *  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)
+ *
+ */
+
+
+/*
+ * Array dimension iterator.
+ * Iterate through the dimensions of array specification.
+ *
+ * This is part of the 4th stage that generates
+ * a c++ source program equivalent to the IL and ST
+ * code.
+ */
+
+/* Given a array_specification_c, iterate through
+ * each subrange, returning the symbol of each subrange
+ * ...array_dimension_iterator_c
+ */
+
+
+
+
+#include "array_dimension_iterator.hh"
+
+
+//#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);
+
+void* array_dimension_iterator_c::iterate_list(list_c *list) {
+  void *res;
+  for (int i = 0; i < list->n; i++) {
+    res = list->elements[i]->accept(*this);
+    if (res != NULL)
+        return res;
+  }
+  return NULL;
+}
+
+/* start off at the first case element once again... */
+void array_dimension_iterator_c::reset(void) {
+  current_array_dimension = NULL;
+}
+
+
+/* initialize the iterator object.
+ * We must be given a reference to a array_specification_c that will be analyzed...
+ */
+array_dimension_iterator_c::array_dimension_iterator_c(symbol_c *symbol) {
+  /* do some consistency check... */
+  array_specification_c* array_spec = dynamic_cast<array_specification_c*>(symbol);
+
+  if (NULL == array_spec) ERROR;
+
+  /* OK. Now initialize this object... */
+  this->array_specification = symbol;
+  reset();
+}
+
+
+
+/* Skip to the next subrange. After object creation,
+ * the object references on subrange _before_ the first, so
+ * this function must be called once to get the object to
+ * reference the first subrange...
+ *
+ * Returns the subrange symbol!
+ */
+symbol_c *array_dimension_iterator_c::next(void) {
+  void *res = array_specification->accept(*this);
+  if (res == NULL) 
+    return NULL;
+
+  return current_array_dimension;
+}
+
+/********************************/
+/* B 1.3.3 - Derived data types */
+/********************************/
+/*  signed_integer DOTDOT signed_integer */
+void *array_dimension_iterator_c::visit(subrange_c *symbol) {
+  if (current_array_dimension == symbol) {
+	current_array_dimension = NULL;
+  }
+  else if (current_array_dimension == NULL) {
+	current_array_dimension = symbol;
+	return symbol;
+  }
+
+  /* Not found! */
+  return NULL;
+}
+
+/* ARRAY '[' array_subrange_list ']' OF non_generic_type_name */
+void *array_dimension_iterator_c::visit(array_specification_c *symbol) {
+  return symbol->array_subrange_list->accept(*this);
+}
+
+/* array_subrange_list ',' subrange */
+void *array_dimension_iterator_c::visit(array_subrange_list_c *symbol) {
+  return iterate_list(symbol);
+}
+