# HG changeset patch
# User mario
# Date 1171479421 -3600
# Node ID 0b472e25eb16e6d188d8eaa60c5ddc5b802aa7db
# Parent  d926ee71f228776c922d6fe5aa2498911e2db895
Adding changes to make the compiler compatible with bison ver 2.3

diff -r d926ee71f228 -r 0b472e25eb16 Makefile
--- a/Makefile	Mon Feb 12 14:06:59 2007 +0100
+++ b/Makefile	Wed Feb 14 19:57:01 2007 +0100
@@ -38,7 +38,7 @@
 
 
 LIBS  = absyntax/absyntax.o absyntax/visitor.o
-LIBS += stage1_2/iec.y.o stage1_2/iec.flex.o
+LIBS += stage1_2/stage1_2.o stage1_2/iec.y.o stage1_2/iec.flex.o 
 
 iec2cc: main.o stage4/generate_cc/generate_cc.o stage4/stage4.o $(LIBS)
 	$(CXX) -o iec2cc main.o stage4/stage4.o stage4/generate_cc/generate_cc.o $(LIBS)
diff -r d926ee71f228 -r 0b472e25eb16 absyntax/absyntax.cc
--- a/absyntax/absyntax.cc	Mon Feb 12 14:06:59 2007 +0100
+++ b/absyntax/absyntax.cc	Wed Feb 14 19:57:01 2007 +0100
@@ -38,8 +38,6 @@
 
 
 
-symbol_c *tree_root = NULL;
-
 
 
 
diff -r d926ee71f228 -r 0b472e25eb16 stage1_2/Makefile
--- a/stage1_2/Makefile	Mon Feb 12 14:06:59 2007 +0100
+++ b/stage1_2/Makefile	Wed Feb 14 19:57:01 2007 +0100
@@ -7,7 +7,8 @@
 
 .PHONY: iec.flex
 
-all: iec.flex.o iec.y.o
+all: iec.flex.o iec.y.o stage1_2.o
+
 
 clean:
 	-rm -f *.o Makefile.depend
@@ -47,3 +48,11 @@
 #how to make things from other directories if they are missing
 ../% /%:
 	$(MAKE) -C $(@D) $(@F)
+
+
+Makefile.depend depend:
+	$(CXX) -MM -MG -I. *.cc \
+	  | perl -pe 's/:/ Makefile.depend:/' > Makefile.depend
+
+include Makefile.depend
+
diff -r d926ee71f228 -r 0b472e25eb16 stage1_2/iec.flex
--- a/stage1_2/iec.flex	Mon Feb 12 14:06:59 2007 +0100
+++ b/stage1_2/iec.flex	Wed Feb 14 19:57:01 2007 +0100
@@ -117,11 +117,14 @@
  */
 #include "../absyntax/absyntax.hh"
 
+
 /* generated by bison.
  * Contains the definition of the token constants, and the
  * token value type YYSTYPE (in our case, a 'const char *')
  */
 #include "iec.y.hh"
+#include "stage1_2_priv.hh"
+
 
 /* Variable defined by the bison parser,
  * where the value of the tokens will be stored
@@ -134,7 +137,11 @@
  * apropriately whenever it comes across an (*#include <filename> *)
  * directive...
  */
+/*
+ NOTE: already defined in iec.y.hh 
 extern const char *current_filename;
+*/
+
 
 /* We will not be using unput() in our flex code... */
 #define YY_NO_UNPUT
@@ -183,19 +190,6 @@
 %}
 
 
-/*********************************************/
-/* Change parse state to body definitions... */
-/*********************************************/
-
-%{
-static int goto_body_state__ = 0;
-
-void cmd_goto_body_state(void) {goto_body_state__ = 1;}
-int  get_goto_body_state(void) {return goto_body_state__;}
-void rst_goto_body_state(void) {goto_body_state__ = 0;}
-%}
-
-
 /***************************************************/
 /* Forward Declaration of functions defined later. */
 /***************************************************/
@@ -362,17 +356,6 @@
 	NULL /* must end with NULL!! */
 	};
 
-
-/*
- * Join two strings together. Allocate space with malloc(3).
- */
-static char *strdup2(const char *a, const char *b) {
-  char *res = (char *)malloc(strlen(a) + strlen(b) + 1);
-
-  if (!res)
-    return NULL;
-  return strcat(strcpy(res, a), b);  /* safe, actually */
-}
 %}
 
 
@@ -1413,12 +1396,12 @@
 
 const char *current_filename;
 
+
+
 int get_identifier_token(const char *identifier_str) {return 0;}
 
 
 
-
-
 int main(int argc, char **argv) {
 
   FILE *in_file;
diff -r d926ee71f228 -r 0b472e25eb16 stage1_2/iec.y
--- a/stage1_2/iec.y	Mon Feb 12 14:06:59 2007 +0100
+++ b/stage1_2/iec.y	Wed Feb 14 19:57:01 2007 +0100
@@ -77,10 +77,9 @@
 #include "../absyntax/absyntax.hh"
 
 /* file with declaration of token constants. Generated by bison! */
-#include "iec.y.hh"
-
-/* file with the declarations of symbol tables... */
-#include "../util/symtable.hh"
+// #include "iec.y.hh"
+
+#include "stage1_2_priv.hh"
 
 
 /* an ugly hack!!
@@ -110,45 +109,30 @@
 extern void error_exit(const char *file_name, int line_no);
 
 
-/*********************************/
-/* The global symbol tables...   */
-/*********************************/
-/* NOTE: declared static because they are not accessed
- *       directly by the lexical parser (flex), but rather
- *       through the function get_identifier_token()
- */
-/* A symbol table to store all the library elements */
-/* e.g.: <function_name , function_decl>
- *       <fb_name , fb_decl>
- *       <type_name , type_decl>
- *       <program_name , program_decl>
- *       <configuration_name , configuration_decl>
- */
-static symtable_c<int, BOGUS_TOKEN_ID> library_element_symtable;
-
-/* A symbol table to store the declared variables of
- * the function currently being parsed...
- */
-static symtable_c<int, BOGUS_TOKEN_ID> variable_name_symtable;
-
 
 /*************************/
 /* global variables...   */
 /*************************/
-static symbol_c *tree_root = NULL;
-
-/* The name of the file currently being parsed...
- * Note that flex accesses and updates this global variable
- * apropriately whenever it comes across an (*#include <filename> *)
- * directive...
- */
-const char *current_filename = NULL;
+/* NOTE: For some strange reason bison ver 2.3 is including these declarations
+ *       in the iec.y.hh file, which is in turn included by flex.
+ *       We cannot therefore define any variables over here, but merely declare 
+ *       their existance (otherwise we get errors when linking the code, since we
+ *       would get a new variable defined each time iec.y.hh is included!).
+ *       Even though the variables are declared 'extern' over here, they will in
+ *       fact be defined towards the end of this same file (i.e. in the prologue)
+ */
 
 /* A global flag used to tell the parser if overloaded funtions should be allowed.
  * The IEC 61131-3 standard allows overloaded funtions in the standard library,
  * but disallows them in user code...
  */
-bool allow_function_overloading = false;
+extern bool allow_function_overloading;
+
+/* A pointer to the root of the parsing tree that will be generated 
+ * by bison.
+ */
+extern symbol_c *tree_root;
+
 
 
 /************************/
@@ -162,20 +146,11 @@
 /* print an error message */
 void print_err_msg(const char *filename, int lineno, const char *additional_error_msg);
 
-
-/************************/
-/* forward declarations */
-/************************/
-/* The functions declared here are defined in iec.flex... */
-void print_include_stack(void);
-void cmd_goto_body_state(void);
-int  get_goto_body_state(void);
-void rst_goto_body_state(void);
-
 %}
 
 
 
+
 %glr-parser
 // %expect-rr 1
 
@@ -206,37 +181,6 @@
 /*****************************/
 /* Prelimenary constructs... */
 /*****************************/
-%type <leaf> start
-
-%type <leaf>	any_identifier
-
-%token <ID>	prev_declared_variable_name_token
-%token <ID>	prev_declared_fb_name_token
-%type <leaf>	prev_declared_variable_name
-%type <leaf>	prev_declared_fb_name
-
-%token  <ID>	prev_declared_simple_type_name_token
-%token  <ID>	prev_declared_subrange_type_name_token
-%token  <ID>	prev_declared_enumerated_type_name_token
-%token  <ID>	prev_declared_array_type_name_token
-%token  <ID>	prev_declared_structure_type_name_token
-%token  <ID>	prev_declared_string_type_name_token
-
-%type  <leaf>	prev_declared_simple_type_name
-%type  <leaf>	prev_declared_subrange_type_name
-%type  <leaf>	prev_declared_enumerated_type_name
-%type  <leaf>	prev_declared_array_type_name
-%type  <leaf>	prev_declared_structure_type_name
-%type  <leaf>	prev_declared_string_type_name
-
-%token <ID>	prev_declared_derived_function_name_token
-%token <ID>	prev_declared_derived_function_block_name_token
-%token <ID>	prev_declared_program_type_name_token
-%type  <leaf>	prev_declared_derived_function_name
-%type  <leaf>	prev_declared_derived_function_block_name
-%type  <leaf>	prev_declared_program_type_name
-
-
 /* A bogus token that, in principle, flex MUST NEVER generate */
 /* USE 1:
  * ======
@@ -256,6 +200,47 @@
 %token BOGUS_TOKEN_ID
 
 
+
+%{
+/* The interface through which bison and flex interact. */
+/* May only be included after the definition of BOGUS_TOKEN_ID */
+#include "stage1_2_priv.hh"
+%}
+
+
+%type <leaf> start
+
+%type <leaf>	any_identifier
+
+%token <ID>	prev_declared_variable_name_token
+%token <ID>	prev_declared_fb_name_token
+%type <leaf>	prev_declared_variable_name
+%type <leaf>	prev_declared_fb_name
+
+%token  <ID>	prev_declared_simple_type_name_token
+%token  <ID>	prev_declared_subrange_type_name_token
+%token  <ID>	prev_declared_enumerated_type_name_token
+%token  <ID>	prev_declared_array_type_name_token
+%token  <ID>	prev_declared_structure_type_name_token
+%token  <ID>	prev_declared_string_type_name_token
+
+%type  <leaf>	prev_declared_simple_type_name
+%type  <leaf>	prev_declared_subrange_type_name
+%type  <leaf>	prev_declared_enumerated_type_name
+%type  <leaf>	prev_declared_array_type_name
+%type  <leaf>	prev_declared_structure_type_name
+%type  <leaf>	prev_declared_string_type_name
+
+%token <ID>	prev_declared_derived_function_name_token
+%token <ID>	prev_declared_derived_function_block_name_token
+%token <ID>	prev_declared_program_type_name_token
+%type  <leaf>	prev_declared_derived_function_name
+%type  <leaf>	prev_declared_derived_function_block_name
+%type  <leaf>	prev_declared_program_type_name
+
+
+
+
 /* The pragmas... */
 %token <ID>	pragma_token
 %type <leaf>	pragma
@@ -488,11 +473,11 @@
 %token STRING
 %token BOOL
 
-%token TIME
-%token DATE
-%token DATE_AND_TIME
+// %token TIME
+// %token DATE
+// %token DATE_AND_TIME
 %token DT
-%token TIME_OF_DAY
+// %token TIME_OF_DAY
 %token TOD
 
 
@@ -783,10 +768,10 @@
 %token FUNCTION_BLOCK
 %token END_FUNCTION_BLOCK
 %token VAR_TEMP
-%token END_VAR
+// %token END_VAR
 %token VAR
-%token NON_RETAIN
-%token END_VAR
+// %token NON_RETAIN
+// %token END_VAR
 
 
 /**********************/
@@ -831,7 +816,7 @@
 %type  <leaf>	transition_name
 
 
-%token ASSIGN
+// %token ASSIGN
 %token ACTION
 %token END_ACTION
 
@@ -942,12 +927,12 @@
 %token END_RESOURCE
 %token VAR_CONFIG
 %token VAR_ACCESS
-%token END_VAR
+// %token END_VAR
 %token WITH
-%token PROGRAM
-%token RETAIN
-%token NON_RETAIN
-%token PRIORITY
+// %token PROGRAM
+// %token RETAIN
+// %token NON_RETAIN
+// %token PRIORITY
 %token SINGLE
 %token INTERVAL
 %token READ_WRITE
@@ -1125,11 +1110,11 @@
 /* intermediate helper symbol for primary_expression */
 %type  <leaf>	function_invocation
 
-%token AND
-%token XOR
-%token OR
-%token MOD
-%token NOT
+// %token AND
+// %token XOR
+// %token OR
+// %token MOD
+// %token NOT
 %token OPER_NE
 %token OPER_GE
 %token OPER_LE
@@ -1148,7 +1133,7 @@
 /* B 3.2.1 Assignment Statements */
 /*********************************/
 %type <leaf> assignment_statement
-%token ASSIGN   /* ":=" */
+// %token ASSIGN   /* ":=" */
 
 
 /*****************************************/
@@ -1161,8 +1146,8 @@
 /* helper symbol for fb_invocation */
 %type <list> param_assignment_list
 
-%token ASSIGN
-%token SENDTO   /* "=>" */
+// %token ASSIGN
+// %token SENDTO   /* "=>" */
 %token RETURN
 
 
@@ -1189,8 +1174,8 @@
 %token END_IF
 
 %token CASE
-%token OF
-%token ELSE
+// %token OF
+// %token ELSE
 %token END_CASE
 
 
@@ -1208,14 +1193,14 @@
 // %type <leaf>	for_list
 
 %token FOR
-%token ASSIGN
-%token TO
+// %token ASSIGN
+// %token TO
 %token BY
 %token DO
 %token END_FOR
 
 %token WHILE
-%token DO
+// %token DO
 %token END_WHILE
 
 %token REPEAT
@@ -5178,6 +5163,21 @@
 extern FILE *yyin;
 extern int yylineno;
 
+
+
+/* A global flag used to tell the parser if overloaded funtions should be allowed.
+ * The IEC 61131-3 standard allows overloaded funtions in the standard library,
+ * but disallows them in user code...
+ */
+bool allow_function_overloading = false;
+
+/* A pointer to the root of the parsing tree that will be generated 
+ * by bison.
+ */
+symbol_c *tree_root;
+
+
+
 /* The following function is called automatically by bison whenever it comes across
  * an error. Unfortunately it calls this function before executing the code that handles
  * the error itself, so we cannot print out the correct line numbers of the error location
@@ -5200,24 +5200,6 @@
   fprintf(stderr, "%s:%d: %s\n", filename, lineno, current_error_msg);
 }
 
-/* Function only called from within flex!
- *
- * search for a symbol in either of the two symbol tables
- * declared above, and return the token id of the first
- * symbol found.
- * Searches first in the variables, and only if not found
- * does it continue searching in the library elements
- */
-int get_identifier_token(const char *identifier_str) {
-//  std::cout << "get_identifier_token(" << identifier_str << "): \n";
-  int token_id;
-
-  if ((token_id = variable_name_symtable.find_value(identifier_str)) == variable_name_symtable.end_value())
-    if ((token_id = library_element_symtable.find_value(identifier_str)) == library_element_symtable.end_value())
-      return identifier_token;
-  return token_id;
-}
-
 
 
 /* convert between an il_operator to a function name */
@@ -5306,31 +5288,6 @@
 
 
 
-/*
- * Join two strings together. Allocate space with malloc(3).
- */
-static char *strdup2(const char *a, const char *b) {
-  char *res = (char *)malloc(strlen(a) + strlen(b) + 1);
-
-  if (!res)
-    return NULL;
-  return strcat(strcpy(res, a), b);  /* safe, actually */
-}
-
-/*
- * Join three strings together. Allocate space with malloc(3).
- */
-static char *strdup3(const char *a, const char *b, const char *c) {
-  char *res = (char *)malloc(strlen(a) + strlen(b) + strlen(c) + 1);
-
-  if (!res)
-    return NULL;
-  return strcat(strcat(strcpy(res, a), b), c);  /* safe, actually */
-}
-
-
-
-
 const char *standard_function_names[] = {
 // 2.5.1.5.1  Type conversion functions
 /*
@@ -5410,7 +5367,7 @@
 #define LIBFILE "ieclib.txt"
 #define DEF_LIBFILENAME LIBDIRECTORY "/" LIBFILE
 
-int stage1_2(const char *filename, const char *includedir, symbol_c **tree_root_ref) {
+int stage1_2__(const char *filename, const char *includedir, symbol_c **tree_root_ref) {
   FILE *in_file = NULL, *lib_file = NULL;
   char *libfilename = NULL;
 
diff -r d926ee71f228 -r 0b472e25eb16 stage1_2/stage1_2.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/stage1_2/stage1_2.cc	Wed Feb 14 19:57:01 2007 +0100
@@ -0,0 +1,167 @@
+/*
+ * (c) 2007 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)
+ *
+ */
+
+
+/*
+ * This file contains the code that calls the stage 1 (lexical anayser) 
+ * and stage 2 (syntax parser) during the first pass.
+ */
+
+
+
+// #include "stage1_2.hh"
+#include "iec.y.hh"
+#include "stage1_2_priv.hh"
+
+
+
+
+
+/**************************************/
+/* The name of the file being parsed. */
+/**************************************/
+/* The name of the file currently being parsed...
+ * Note that flex accesses and updates this global variable
+ * apropriately whenever it comes across an (*#include <filename> *)
+ * directive...
+ * ... and bison will use it when producing error messages.
+ * Note that bison also sets this variable correctly to the first
+ * file being parsed.
+ */
+const char *current_filename = NULL;
+
+
+
+
+/*****************************************************/
+/* Controlling the entry to the st_il_state in flex. */
+/*****************************************************/
+
+static int goto_body_state__ = 0;
+
+void cmd_goto_body_state(void) {goto_body_state__ = 1;}
+int  get_goto_body_state(void) {return goto_body_state__;}
+void rst_goto_body_state(void) {goto_body_state__ = 0;}
+
+
+
+/*********************************/
+/* The global symbol tables...   */
+/*********************************/
+/* NOTE: only accessed indirectly by the lexical parser (flex)
+ *       through the function get_identifier_token()
+ */
+/* NOTE: BOGUS_TOKEN_ID is defined in the bison generated file iec.y.hh.
+ *       We need this constant defined before we can declare the symbol tables.
+ *       However, we cannot #include "iec.y.hh" in this file (stage1_2_priv.hh) directly
+ *       because of the way bison ver. 3.2 is copying all declarations in the prologue
+ *       of iec.y to the iec.y.hh file (including an #include stage1_2_priv.hh).
+ *       So, if we were to include "iec.y.hh" here, we would get a circular include.
+ *       All this means that whoever includes this file (stage1_2_priv.hh) will need
+ *       to take care to first inlcude iec.y.hh !!
+ */ 
+/* A symbol table to store all the library elements */
+/* e.g.: <function_name , function_decl>
+ *       <fb_name , fb_decl>
+ *       <type_name , type_decl>
+ *       <program_name , program_decl>
+ *       <configuration_name , configuration_decl>
+ */
+/* static */ symtable_c<int, BOGUS_TOKEN_ID> library_element_symtable;
+
+/* A symbol table to store the declared variables of
+ * the function currently being parsed...
+ */
+/* static */ symtable_c<int, BOGUS_TOKEN_ID> variable_name_symtable;
+
+
+/* Function only called from within flex!
+ *
+ * search for a symbol in either of the two symbol tables
+ * declared above, and return the token id of the first
+ * symbol found.
+ * Searches first in the variables, and only if not found
+ * does it continue searching in the library elements
+ */
+int get_identifier_token(const char *identifier_str) {
+//  std::cout << "get_identifier_token(" << identifier_str << "): \n";
+  int token_id;
+
+  if ((token_id = variable_name_symtable.find_value(identifier_str)) == variable_name_symtable.end_value())
+    if ((token_id = library_element_symtable.find_value(identifier_str)) == library_element_symtable.end_value())
+      return identifier_token;
+  return token_id;
+}
+
+
+/************************/
+/* Utility Functions... */
+/************************/
+
+/*
+ * Join two strings together. Allocate space with malloc(3).
+ */
+char *strdup2(const char *a, const char *b) {
+  char *res = (char *)malloc(strlen(a) + strlen(b) + 1);
+
+  if (!res)
+    return NULL;
+  return strcat(strcpy(res, a), b);  /* safe, actually */
+}
+
+/*
+ * Join three strings together. Allocate space with malloc(3).
+ */
+char *strdup3(const char *a, const char *b, const char *c) {
+  char *res = (char *)malloc(strlen(a) + strlen(b) + strlen(c) + 1);
+
+  if (!res)
+    return NULL;
+  return strcat(strcat(strcpy(res, a), b), c);  /* safe, actually */
+}
+
+
+
+
+
+
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+/***********************************************************************/
+
+
+int stage1_2__(const char *filename, const char *includedir, symbol_c **tree_root_ref);
+
+
+int stage1_2(const char *filename, const char *includedir, symbol_c **tree_root_ref) {
+  return stage1_2__(filename, includedir, tree_root_ref);
+}
+
diff -r d926ee71f228 -r 0b472e25eb16 stage1_2/stage1_2_priv.hh
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/stage1_2/stage1_2_priv.hh	Wed Feb 14 19:57:01 2007 +0100
@@ -0,0 +1,135 @@
+/*
+ * (c) 2007 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)
+ *
+ */
+
+
+/*
+ * The private interface to stage1_2.cc 
+ */
+
+
+
+/* file with the declarations of symbol tables... */
+#include "../util/symtable.hh"
+
+
+
+/*
+ * This file includes the interface through which the lexical parser (stage 1 - flex)
+ * and the syntax analyser (stage 2 - bison) interact between themselves.
+ *
+ * This is mostly through direct access to shared global variables, however some
+ * of the global variables will only be accessed through some accessor functions.
+ *
+ * This file also includes some utility functions (strdupX() ) that are both used
+ * in the lexical and syntax analysers.
+ */
+
+
+
+
+
+/*********************************************/
+/* print the include file stack to stderr... */
+/*********************************************/
+/* This is a service that flex provides to bison... */
+void print_include_stack(void);
+
+
+
+/**************************************/
+/* The name of the file being parsed. */
+/**************************************/
+/* The name of the file currently being parsed...
+ * Note that flex accesses and updates this global variable
+ * apropriately whenever it comes across an (*#include <filename> *)
+ * directive...
+ * ... and bison will use it when producing error messages.
+ * Note that bison also sets this variable correctly to the first
+ * file being parsed.
+ */
+extern const char *current_filename;
+
+
+
+/*****************************************************/
+/* Controlling the entry to the st_il_state in flex. */
+/*****************************************************/
+void cmd_goto_body_state(void);
+int  get_goto_body_state(void);
+void rst_goto_body_state(void);
+
+
+/*********************************/
+/* The global symbol tables...   */
+/*********************************/
+/* NOTE: only accessed indirectly by the lexical parser (flex)
+ *       through the function get_identifier_token()
+ */
+/* NOTE: BOGUS_TOKEN_ID is defined in the bison generated file iec.y.hh.
+ *       We need this constant defined before we can declare the symbol tables.
+ *       However, we cannot #include "iec.y.hh" in this file (stage1_2_priv.hh) directly
+ *       because of the way bison ver. 3.2 is copying all declarations in the prologue
+ *       of iec.y to the iec.y.hh file (including an #include stage1_2_priv.hh).
+ *       So, if we were to include "iec.y.hh" here, we would get a circular include.
+ *       All this means that whoever includes this file (stage1_2_priv.hh) will need
+ *       to take care to first inlcude iec.y.hh !!
+ */ 
+/* A symbol table to store all the library elements */
+/* e.g.: <function_name , function_decl>
+ *       <fb_name , fb_decl>
+ *       <type_name , type_decl>
+ *       <program_name , program_decl>
+ *       <configuration_name , configuration_decl>
+ */
+extern symtable_c<int, BOGUS_TOKEN_ID> library_element_symtable;
+
+/* A symbol table to store the declared variables of
+ * the function currently being parsed...
+ */
+extern symtable_c<int, BOGUS_TOKEN_ID> variable_name_symtable;
+
+/* Function only called from within flex!
+ *
+ * search for a symbol in either of the two symbol tables
+ * declared above, and return the token id of the first
+ * symbol found.
+ * Searches first in the variables, and only if not found
+ * does it continue searching in the library elements
+ */
+int get_identifier_token(const char *identifier_str);
+
+
+
+/************************/
+/* Utility Functions... */
+/************************/
+
+/* Join two strings together. Allocate space with malloc(3). */
+char *strdup2(const char *a, const char *b);
+
+/* Join three strings together. Allocate space with malloc(3). */
+char *strdup3(const char *a, const char *b, const char *c);
+
+
+