--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/absyntax_utils/add_en_eno_param_decl.hh	Wed Sep 02 14:05:27 2009 +0200
@@ -0,0 +1,96 @@
+/*
+ * (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 "../absyntax/visitor.hh"
+
+
+class add_en_eno_param_decl_c : public null_visitor_c {
+  public:
+    static symbol_c *add_to(symbol_c *tree_root);
+    ~add_en_eno_param_decl_c(void);
+
+  private:
+    /* this class is a singleton. So we need a pointer to the single instance... */
+    static add_en_eno_param_decl_c *singleton;
+
+    /* flags to remember whether the EN and/or ENO parameters have already
+     * been explicitly declared by the user in the IEC 61131-3 source code we are parsing...
+     */
+    bool en_declared;
+    bool eno_declared;
+
+  private:
+    void* iterate_list(list_c *list);
+    input_declarations_c  *build_en_param (void);
+    output_declarations_c *build_eno_param(void);
+
+  private:
+    /***************************/
+    /* B 0 - Programming Model */
+    /***************************/
+    void *visit(library_c *symbol);
+
+    /***********************/
+    /* B 1.5.1 - Functions */
+    /***********************/
+    void *visit(function_declaration_c *symbol);
+    /* intermediate helper symbol for function_declaration */
+    void *visit(var_declarations_list_c *symbol);
+
+    /******************************************/
+    /* B 1.4.3 - Declaration & Initialisation */
+    /******************************************/
+    void *visit(input_declarations_c *symbol);
+    void *visit(input_declaration_list_c *symbol);
+    void *visit(en_param_declaration_c *symbol);
+    void *visit(eno_param_declaration_c *symbol);
+    void *visit(output_declarations_c *symbol);
+    void *visit(var_init_decl_list_c *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 *visit(function_block_declaration_c *symbol);
+
+}; // function_param_iterator_c
+
+
+
+
+
+
+