--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/stage3/constant_folding.hh	Tue Jun 05 19:17:29 2012 +0200
@@ -0,0 +1,103 @@
+/*
+ *  matiec - a compiler for the programming languages defined in IEC 61131-3
+ *
+ *  Copyright (C) 2009-2012  Mario de Sousa (msousa@fe.up.pt)
+ *  Copyright (C) 2012       Manuele Conti (conti.ma@alice.it)
+ *
+ *  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)
+ *
+ */
+
+/* Determine the data type of an constant expression.
+ * A reference to the relevant type definition is returned.
+ *
+ * For example:
+ *       2 + 3       -> returns reference 
+ *       22.2 - 5    -> returns reference
+ *       etc...
+ */
+
+#include <vector>
+#include "../absyntax_utils/absyntax_utils.hh"
+
+
+
+class constant_folding_c : public iterator_visitor_c {
+    search_varfb_instance_type_c *search_varfb_instance_type;
+    search_base_type_c search_base_type;
+    int error_count;
+    int current_display_error_level;
+
+public:
+	constant_folding_c(symbol_c *symbol = NULL);
+	virtual ~constant_folding_c(void);
+	int get_error_count();
+
+private:
+    /*********************/
+    /* B 1.2 - Constants */
+    /*********************/
+    /******************************/
+    /* B 1.2.1 - Numeric Literals */
+    /******************************/
+    void *visit(real_c *symbol);
+    void *visit(integer_c *symbol);
+    void *visit(neg_real_c *symbol);
+    void *visit(neg_integer_c *symbol);
+    void *visit(binary_integer_c *symbol);
+    void *visit(octal_integer_c *symbol);
+    void *visit(hex_integer_c *symbol);
+    void *visit(integer_literal_c *symbol);
+    void *visit(real_literal_c *symbol);
+    void *visit(bit_string_literal_c *symbol);
+    void *visit(boolean_literal_c *symbol);
+    void *visit(boolean_true_c *symbol);
+    void *visit(boolean_false_c *symbol);
+
+    /***************************************/
+    /* B.3 - Language ST (Structured Text) */
+    /***************************************/
+    /***********************/
+    /* B 3.1 - Expressions */
+    /***********************/
+    void *visit(or_expression_c *symbol);
+    void *visit(xor_expression_c *symbol);
+    void *visit(and_expression_c *symbol);
+    void *visit(equ_expression_c *symbol);
+    void *visit(notequ_expression_c *symbol);
+    void *visit(lt_expression_c *symbol);
+    void *visit(gt_expression_c *symbol);
+    void *visit(le_expression_c *symbol);
+    void *visit(ge_expression_c *symbol);
+    void *visit(add_expression_c *symbol);
+    void *visit(sub_expression_c *symbol);
+    void *visit(mul_expression_c *symbol);
+    void *visit(div_expression_c *symbol);
+    void *visit(mod_expression_c *symbol);
+    void *visit(power_expression_c *symbol);
+    void *visit(neg_expression_c *symbol);
+    void *visit(not_expression_c *symbol);
+};
+